washingtonpost:

How some artificial sweeteners might lead to diabetes.

Others, however, are much more critical. “On this evidence, I’d agree that lab mice shouldn’t have lots of sweeteners in their drinking water,” writes Catherine Collins, a dietitian at St. George’s Hospital in London,  in a statement distributed by the Science Media Centre. Lab mice get a much lower part of their calories from carbohydrates than humans do, she points out. “Our naturally higher carbohydrate intake has generated bowel bacteria happily digesting whatever we swallow, and their symbiotic relationship with our bowel cells and beyond is testimony to this.”
The data on humans, from just seven people, of which four show an effect, are far from convincing, O’Rahilly says. “If this had been sent to a clinical research journal there would have been a lot of questions.” Previous research also seems to point in a different direction. A large epidemiological study involving tens of thousands of people published last year found a connection between sugar-sweetened beverages and diabetes, but not between artificially sweetened soft drinks and diabetes.
Artificial sweeteners may contribute to diabetes, controversial study finds

washingtonpost:

How some artificial sweeteners might lead to diabetes.

Others, however, are much more critical. “On this evidence, I’d agree that lab mice shouldn’t have lots of sweeteners in their drinking water,” writes Catherine Collins, a dietitian at St. George’s Hospital in London,  in a statement distributed by the Science Media Centre. Lab mice get a much lower part of their calories from carbohydrates than humans do, she points out. “Our naturally higher carbohydrate intake has generated bowel bacteria happily digesting whatever we swallow, and their symbiotic relationship with our bowel cells and beyond is testimony to this.”

The data on humans, from just seven people, of which four show an effect, are far from convincing, O’Rahilly says. “If this had been sent to a clinical research journal there would have been a lot of questions.” Previous research also seems to point in a different direction. A large epidemiological study involving tens of thousands of people published last year found a connection between sugar-sweetened beverages and diabetes, but not between artificially sweetened soft drinks and diabetes.

Artificial sweeteners may contribute to diabetes, controversial study finds

artificial sweeteners infographic science diabetes microbiome

Artificial sweeteners may contribute to diabetes, controversial study finds


When it comes to the sweet stuff, science often turns sour. Almost every study that has linked sugar to problems such as tooth decay, diabetes, obesity, or even childhood violence has come under heavy fire. Nonetheless, the World Health Organization released draft guidelines earlier this year that halved the recommended maximum sugar intake.
Now, new research is suggesting that synthetic sweeteners like saccharin might not be a great alternative. They could have a negative effect on gut microbes and thus lead to a higher risk of diabetes, researchers say. But other scientists say the results fly in the face of previous research and may be wrong. “It would be unfortunate if this data were to influence public policy,” says endocrinologist Stephen O’Rahilly, who heads the metabolic research laboratories at the University of Cambridge in the United Kingdom.
Scientists are only beginning to understand what role the billions of microbial cells colonizing the human gut play in diet and disease. Some microbial boarders are known to be crucial in breaking down nutrients in our diet. Studies have also shown that overweight people tend to have different bacteria in their intestines than slim people, but it is not clear what exactly the link is and whether the bacteria somehow cause obesity or diabetes.
Scientists at the Weizmann Institute of Science in Rehovot, Israel, started by feeding mice with water that contained either sugar or one of three noncaloric sweeteners: aspartame, sucralose, or saccharin. After 11 weeks, the mice fed with artificial sweeteners showed an unusually high spike in blood glucose levels when given a glucose meal, a condition called glucose intolerance that is seen as an early stage in the development of diabetes. But when the mice were given antibiotics for 4 weeks, glucose intolerance didn’t occur, indicating that gut microbes may play a role.
The researchers also found that certain types of gut microbes were more common in mice fed saccharin. By transferring the intestinal bacteria from these mice to germ-free mice, the researchers also transferred their glucose intolerance. They even took gut bacteria from healthy mice, cultured them in the laboratory with saccharin, and then transferred them into germ-free mice and showed that these mice, too, developed glucose intolerance. Molecules produced by some of the bacteria may increase glucose production in the body and push blood glucose levels out of balance, the researchers suggest.
To confirm that their findings are relevant to humans as well, the researchers followed seven individuals given a high dose of saccharin—5 milligrams per kilogram of body weight, the Food and Drug Administration’s maximum acceptable daily intake—on 6 consecutive days. Four of these individuals also began showing signs of glucose intolerance, the researchers report online today in Nature, suggesting that artificial sweeteners “may have directly contributed to enhancing the exact [diabetes] epidemic that they themselves were intended to fight.”
It’s “really fascinating work,” writes Peter Turnbaugh, a microbiologist at Harvard University, in an e-mail. “There have been some hints in the literature that sweeteners may alter the gut microbiota, but this is by far the most in-depth analysis I’ve seen to date.” Still, he adds, “there’s a lot more basic biology that will need to be worked out to fully appreciate the mechanisms that cause sweeteners to alter gut microbial community composition and function, and how in turn this shapes host metabolism.”
Michael Blaut, a microbiologist at the German Institute of Human Nutrition in Potsdam, Germany, says the mouse data are “believable and remarkable,” but says he has a hard time imagining a mechanism that would account for three compounds as chemically different as aspartame, saccharin, and sucralose leading to the same changes in the gut microbiome.
Others, however, are much more critical. “On this evidence, I’d agree that lab mice shouldn’t have lots of sweeteners in their drinking water,” writes Catherine Collins, a dietitian at St. George’s Hospital in London,  in a statement distributed by the Science Media Centre. Lab mice get a much lower part of their calories from carbohydrates than humans do, she points out. “Our naturally higher carbohydrate intake has generated bowel bacteria happily digesting whatever we swallow, and their symbiotic relationship with our bowel cells and beyond is testimony to this.”
The data on humans, from just seven people, of which four show an effect, are far from convincing, O’Rahilly says. “If this had been sent to a clinical research journal there would have been a lot of questions.” Previous research also seems to point in a different direction. A large epidemiological study involving tens of thousands of people published last year found a connection between sugar-sweetened beverages and diabetes, but not between artificially sweetened soft drinks and diabetes.
"We are the first to admit that the human arm in the study has only preliminary results on a small subset of individuals,” says computational biologist Eran Segal, one of the study authors. But some studies in the past also found an association between artificial sweeteners and risk of diabetes, he says. “The lack of conclusive data and a mechanism in such an important subject was at the basis of us looking into this subject.”
One possible explanation for the discrepancy with large-scale epidemiological studies is that the new study centers on saccharin, a sweetener not used in any of the major soft drinks. In early studies, the researchers also tested aspartame—by far the most widely used soft drink sweetener—but the observed effect was smaller, and they dropped it. “The authors are confounding their conclusions by addressing all these noncaloric artificial sweeteners together,” says Brian Ratcliffe, a nutrition researcher at Robert Gordon University in Aberdeen, U.K. That’s why the title of the paper, “Artificial sweeteners induce glucose intolerance by altering the gut microbiota,” is misleading, he says. “I cannot believe the journal allowed that title.” Still, he says, the data “certainly does suggest that there is something more that needs to be explored about saccharin.”
In the meantime, the study shouldn’t keep people from lowering their sugar intake by choosing artificially sweetened beverages, says Jim Mann, a researcher at the University of Otago, Dunedin, in New Zealand. “We have always known that artificial sweeteners don’t help everybody lose weight, but they are certainly helpful for some people,” he says. And Mann has another tip: "Water is a very useful way of quenching thirst.”

Artificial sweeteners may contribute to diabetes, controversial study finds

When it comes to the sweet stuff, science often turns sour. Almost every study that has linked sugar to problems such as tooth decay, diabetes, obesity, or even childhood violence has come under heavy fire. Nonetheless, the World Health Organization released draft guidelines earlier this year that halved the recommended maximum sugar intake.

Now, new research is suggesting that synthetic sweeteners like saccharin might not be a great alternative. They could have a negative effect on gut microbes and thus lead to a higher risk of diabetes, researchers say. But other scientists say the results fly in the face of previous research and may be wrong. “It would be unfortunate if this data were to influence public policy,” says endocrinologist Stephen O’Rahilly, who heads the metabolic research laboratories at the University of Cambridge in the United Kingdom.

Scientists are only beginning to understand what role the billions of microbial cells colonizing the human gut play in diet and disease. Some microbial boarders are known to be crucial in breaking down nutrients in our diet. Studies have also shown that overweight people tend to have different bacteria in their intestines than slim people, but it is not clear what exactly the link is and whether the bacteria somehow cause obesity or diabetes.

Scientists at the Weizmann Institute of Science in Rehovot, Israel, started by feeding mice with water that contained either sugar or one of three noncaloric sweeteners: aspartame, sucralose, or saccharin. After 11 weeks, the mice fed with artificial sweeteners showed an unusually high spike in blood glucose levels when given a glucose meal, a condition called glucose intolerance that is seen as an early stage in the development of diabetes. But when the mice were given antibiotics for 4 weeks, glucose intolerance didn’t occur, indicating that gut microbes may play a role.

The researchers also found that certain types of gut microbes were more common in mice fed saccharin. By transferring the intestinal bacteria from these mice to germ-free mice, the researchers also transferred their glucose intolerance. They even took gut bacteria from healthy mice, cultured them in the laboratory with saccharin, and then transferred them into germ-free mice and showed that these mice, too, developed glucose intolerance. Molecules produced by some of the bacteria may increase glucose production in the body and push blood glucose levels out of balance, the researchers suggest.

To confirm that their findings are relevant to humans as well, the researchers followed seven individuals given a high dose of saccharin—5 milligrams per kilogram of body weight, the Food and Drug Administration’s maximum acceptable daily intake—on 6 consecutive days. Four of these individuals also began showing signs of glucose intolerance, the researchers report online today in Nature, suggesting that artificial sweeteners “may have directly contributed to enhancing the exact [diabetes] epidemic that they themselves were intended to fight.”

It’s “really fascinating work,” writes Peter Turnbaugh, a microbiologist at Harvard University, in an e-mail. “There have been some hints in the literature that sweeteners may alter the gut microbiota, but this is by far the most in-depth analysis I’ve seen to date.” Still, he adds, “there’s a lot more basic biology that will need to be worked out to fully appreciate the mechanisms that cause sweeteners to alter gut microbial community composition and function, and how in turn this shapes host metabolism.”

Michael Blaut, a microbiologist at the German Institute of Human Nutrition in Potsdam, Germany, says the mouse data are “believable and remarkable,” but says he has a hard time imagining a mechanism that would account for three compounds as chemically different as aspartame, saccharin, and sucralose leading to the same changes in the gut microbiome.

Others, however, are much more critical. “On this evidence, I’d agree that lab mice shouldn’t have lots of sweeteners in their drinking water,” writes Catherine Collins, a dietitian at St. George’s Hospital in London,  in a statement distributed by the Science Media Centre. Lab mice get a much lower part of their calories from carbohydrates than humans do, she points out. “Our naturally higher carbohydrate intake has generated bowel bacteria happily digesting whatever we swallow, and their symbiotic relationship with our bowel cells and beyond is testimony to this.”

The data on humans, from just seven people, of which four show an effect, are far from convincing, O’Rahilly says. “If this had been sent to a clinical research journal there would have been a lot of questions.” Previous research also seems to point in a different direction. A large epidemiological study involving tens of thousands of people published last year found a connection between sugar-sweetened beverages and diabetes, but not between artificially sweetened soft drinks and diabetes.

"We are the first to admit that the human arm in the study has only preliminary results on a small subset of individuals,” says computational biologist Eran Segal, one of the study authors. But some studies in the past also found an association between artificial sweeteners and risk of diabetes, he says. “The lack of conclusive data and a mechanism in such an important subject was at the basis of us looking into this subject.”

One possible explanation for the discrepancy with large-scale epidemiological studies is that the new study centers on saccharin, a sweetener not used in any of the major soft drinks. In early studies, the researchers also tested aspartame—by far the most widely used soft drink sweetener—but the observed effect was smaller, and they dropped it. “The authors are confounding their conclusions by addressing all these noncaloric artificial sweeteners together,” says Brian Ratcliffe, a nutrition researcher at Robert Gordon University in Aberdeen, U.K. That’s why the title of the paper, “Artificial sweeteners induce glucose intolerance by altering the gut microbiota,” is misleading, he says. “I cannot believe the journal allowed that title.” Still, he says, the data “certainly does suggest that there is something more that needs to be explored about saccharin.”

In the meantime, the study shouldn’t keep people from lowering their sugar intake by choosing artificially sweetened beverages, says Jim Mann, a researcher at the University of Otago, Dunedin, in New Zealand. “We have always known that artificial sweeteners don’t help everybody lose weight, but they are certainly helpful for some people,” he says. And Mann has another tip: "Water is a very useful way of quenching thirst.”

artificial sweeteners text article science microbiome diabetes health nutrition glucose saccharin aspartame sucralose

mrcaptaincook:

mindblowingscience:

Artificial sweeteners linked to obesity epidemic, scientists say

Artificial sweeteners may exacerbate, rather than prevent, metabolic disorders such as Type 2 diabetes, a study suggests.
Calorie-free artificial sweeteners are often chosen by dieters in part because they are thought not to raise blood sugar levels.
In Wednesday’s issue of the journal Nature, researchers report that artificial sweeteners increase the blood sugar levels in both mice and humans by interfering with microbes in the gut.Increased blood sugar levels are an early indicator of Type 2 diabetes and metabolic disease.
The increase in consumption of artificial sweeteners coincides with the obesity and diabetes epidemics, Eran Segal of the Weizmann Institute of Science in Rehovot, Israel, and his co-authors said.
"Our findings suggest that non-caloric artificial sweeteners may have directly contributed to enhancing the exact epidemic that they themselves were intended to fight."
Link to gut bacteria
The study included a series of experiments.
Mice whose drinking water was supplemented with glucose and a sweetener developed glucose intolerance compared with mice drinking water alone, or water with just sugar in it. The effect occurred both in mice fed normal chow and those on a high-fat diet.
When antibiotics were used to kill off gut bacteria, the artificial sweetener effect on glucose intolerance in mice fed either diet was restored to normal.
Taken together, the data indicate that artificial sweeteners “may contribute to, rather than alleviate, obesity-related metabolic conditions, by altering the composition and function of bacterial populations in the gut,” Cathryn Nagler and Taylor Feehley of the pathology department at the University of Chicago said in a journal commentary.
In the human part of the research, gut bacteria were analyzed from 381 non-diabetics averaging age 43 who were participating in an ongoing nutrition study.  They found differences in the gut bacteria among those who consumed artificial sweeteners compared with those who did not.
Artificial sweetener consumers showed “markers” for diabetes, such as raised blood sugar levels and glucose intolerance.
More research needed 
In the final portion of the study, seven human volunteers who didn’t normally consume artificial sweeteners added it to their diets for seven days. After four days, blood glucose levels rose and the makeup of their gut bacteria changed in half of the participants, just as in the mice experiment.
To confirm the findings, the researchers also transferred feces from people who consume artificial sweeteners into mice that were bred to have sterile intestines and never consumed it before. The mice who had saccharin became glucose intolerant, which suggests that the artificial sweetener caused the unhealthy effect.
It could be that artificial sweeteners lead to an expansion of bacterial species that extract energy from food that often gets stored as fat, contributing to obesity, Nagler said. It’s also possible the sweeteners could suppress the growth of other bacteria that seem to stave off insulin resistance, she said.
The commentators suggested studies to identify specific bacterial populations that promote resistance to weight gain or improve glucose tolerance could be useful as treatments.
Other experts who were not involved in the research called the findings intriguing, but noted that the human findings in particular were very preliminary in terms of considering changes to nutrition recommendations.
"This research raises caution that [non-caloric artificial sweeteners] may not represent the ‘innocent magic bullet’ they were intended to be to help with the obesity and diabetes epidemics, but it does not yet provide sufficient evidence to alter public health and clinical practice," said Nita Forouhi, program leader at the Medical Research Council’s epidemiology unit at Cambridge University.


"…Not everyone agrees with the design the researchers used to address the question about artificial sweeteners and weight gain. Christopher Gardner, a food scientist at Stanford University who didn’t participate in the study, says that the fact that the researchers gave the FDA’s maximal acceptable daily intake of saccharin to the human participants — about 5 mg / kg body weight per day — isn’t ideal. In a real-life setting, that dose would be the equivalent to a 150-pound person consuming 8.5 12-ounce sodas per day, or 42 packets of pink Sweet ‘n Low per day.* “That may be ‘acceptable’ according to some set of guidelines,” Gardner wrote in an email, “but it should be noted that realistically this is a very high dose they are using and one that wouldn’t be consumed by a typical consumer…”
 8.5 12-ounce sodas per day, or 42 packets of pink Sweet ‘n Low per day.* 
*article linked below has the numbers switched
(source)
so sustained, excessive consumption results in a possible concern? compare that to actual sugar, where serious known issues are highly likely with much lower quantities…
also, not all artificial sweeteners are the same. this write up fails to mention which ones the study was looking at. they were: aspartame, sucralose, saccharin

Artificial sweeteners induce glucose intolerance by altering the gut microbiota

Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage.

"A team led by Eran Elinav of the Weizmann Institute of Science in Rehovot, Israel, fed mice various sweeteners — saccharin, sucralose and aspartame — and found that after 11 weeks, the animals displayed glucose intolerance, a marker of propensity for metabolic disorders.
To simulate the real-world situation of people with varying risks of these diseases, the team fed some mice a normal diet, and some a high-fat diet, and spiked their water either with glucose alone, or with glucose and one of the sweeteners, saccharin. The mice fed saccharin developed a marked glucose intolerance compared to those fed only glucose. But when the animals were given antibiotics to kill their gut bacteria, glucose intolerance was prevented. And when the researchers transplanted faeces from the glucose-intolerant saccharin-fed mice into the guts of mice bred to have sterile intestines, those mice also became glucose intolerant, indicating that saccharin was causing the microbiome to become unhealthy.
Elinav’s team also used data from an on­going clinical nutrition study that has recruited nearly 400 people in Israel. The researchers noted a correlation between clinical signs of metabolic disorder — such as increasing weight or decreasing efficiency of glucose metabolism — and consumption of artificial sweeteners.
But “this is a bit chicken-and-egg”, says Elinav. “If you are putting on weight, you are more likely to turn to diet food. It doesn’t necessarily mean the diet food caused you to put on weight.”
So his team recruited seven lean and healthy volunteers, who did not normally use artificial sweeteners, for a small prospective study. The recruits consumed the maximum acceptable daily dose of artificial sweeteners for a week. Four became glucose intolerant, and their gut microbiomes shifted towards a balance already known to be associated with susceptibility to metabolic diseases, but the other three seemed to be resistant to saccharin’s effects. “This underlines the importance of personalized nutrition — not everyone is the same,” says Elinav.” Sugar substitutes linked to obesity

mrcaptaincook:

mindblowingscience:

Artificial sweeteners linked to obesity epidemic, scientists say

Artificial sweeteners may exacerbate, rather than prevent, metabolic disorders such as Type 2 diabetes, a study suggests.

Calorie-free artificial sweeteners are often chosen by dieters in part because they are thought not to raise blood sugar levels.

In Wednesday’s issue of the journal Nature, researchers report that artificial sweeteners increase the blood sugar levels in both mice and humans by interfering with microbes in the gut.Increased blood sugar levels are an early indicator of Type 2 diabetes and metabolic disease.

The increase in consumption of artificial sweeteners coincides with the obesity and diabetes epidemics, Eran Segal of the Weizmann Institute of Science in Rehovot, Israel, and his co-authors said.

"Our findings suggest that non-caloric artificial sweeteners may have directly contributed to enhancing the exact epidemic that they themselves were intended to fight."

Link to gut bacteria

The study included a series of experiments.

Mice whose drinking water was supplemented with glucose and a sweetener developed glucose intolerance compared with mice drinking water alone, or water with just sugar in it. The effect occurred both in mice fed normal chow and those on a high-fat diet.

When antibiotics were used to kill off gut bacteria, the artificial sweetener effect on glucose intolerance in mice fed either diet was restored to normal.

Taken together, the data indicate that artificial sweeteners “may contribute to, rather than alleviate, obesity-related metabolic conditions, by altering the composition and function of bacterial populations in the gut,” Cathryn Nagler and Taylor Feehley of the pathology department at the University of Chicago said in a journal commentary.

In the human part of the research, gut bacteria were analyzed from 381 non-diabetics averaging age 43 who were participating in an ongoing nutrition study.  They found differences in the gut bacteria among those who consumed artificial sweeteners compared with those who did not.

Artificial sweetener consumers showed “markers” for diabetes, such as raised blood sugar levels and glucose intolerance.

More research needed

In the final portion of the study, seven human volunteers who didn’t normally consume artificial sweeteners added it to their diets for seven days. After four days, blood glucose levels rose and the makeup of their gut bacteria changed in half of the participants, just as in the mice experiment.

To confirm the findings, the researchers also transferred feces from people who consume artificial sweeteners into mice that were bred to have sterile intestines and never consumed it before. The mice who had saccharin became glucose intolerant, which suggests that the artificial sweetener caused the unhealthy effect.

It could be that artificial sweeteners lead to an expansion of bacterial species that extract energy from food that often gets stored as fat, contributing to obesity, Nagler said. It’s also possible the sweeteners could suppress the growth of other bacteria that seem to stave off insulin resistance, she said.

The commentators suggested studies to identify specific bacterial populations that promote resistance to weight gain or improve glucose tolerance could be useful as treatments.

Other experts who were not involved in the research called the findings intriguing, but noted that the human findings in particular were very preliminary in terms of considering changes to nutrition recommendations.

"This research raises caution that [non-caloric artificial sweeteners] may not represent the ‘innocent magic bullet’ they were intended to be to help with the obesity and diabetes epidemics, but it does not yet provide sufficient evidence to alter public health and clinical practice," said Nita Forouhi, program leader at the Medical Research Council’s epidemiology unit at Cambridge University.

"…Not everyone agrees with the design the researchers used to address the question about artificial sweeteners and weight gain. Christopher Gardner, a food scientist at Stanford University who didn’t participate in the study, says that the fact that the researchers gave the FDA’s maximal acceptable daily intake of saccharin to the human participants — about 5 mg / kg body weight per day — isn’t ideal. In a real-life setting, that dose would be the equivalent to a 150-pound person consuming 8.5 12-ounce sodas per day, or 42 packets of pink Sweet ‘n Low per day.* “That may be ‘acceptable’ according to some set of guidelines,” Gardner wrote in an email, “but it should be noted that realistically this is a very high dose they are using and one that wouldn’t be consumed by a typical consumer…”

 8.5 12-ounce sodas per day, or 42 packets of pink Sweet ‘n Low per day.* 

*article linked below has the numbers switched

(source)

so sustained, excessive consumption results in a possible concern? compare that to actual sugar, where serious known issues are highly likely with much lower quantities…

also, not all artificial sweeteners are the same. this write up fails to mention which ones the study was looking at. they were: aspartame, sucralose, saccharin

Artificial sweeteners induce glucose intolerance by altering the gut microbiota

Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage.

"A team led by Eran Elinav of the Weizmann Institute of Science in Rehovot, Israel, fed mice various sweeteners — saccharin, sucralose and aspartame — and found that after 11 weeks, the animals displayed glucose intolerance, a marker of propensity for metabolic disorders.

To simulate the real-world situation of people with varying risks of these diseases, the team fed some mice a normal diet, and some a high-fat diet, and spiked their water either with glucose alone, or with glucose and one of the sweeteners, saccharin. The mice fed saccharin developed a marked glucose intolerance compared to those fed only glucose. But when the animals were given antibiotics to kill their gut bacteria, glucose intolerance was prevented. And when the researchers transplanted faeces from the glucose-intolerant saccharin-fed mice into the guts of mice bred to have sterile intestines, those mice also became glucose intolerant, indicating that saccharin was causing the microbiome to become unhealthy.

Elinav’s team also used data from an on­going clinical nutrition study that has recruited nearly 400 people in Israel. The researchers noted a correlation between clinical signs of metabolic disorder — such as increasing weight or decreasing efficiency of glucose metabolism — and consumption of artificial sweeteners.

But “this is a bit chicken-and-egg”, says Elinav. “If you are putting on weight, you are more likely to turn to diet food. It doesn’t necessarily mean the diet food caused you to put on weight.”

So his team recruited seven lean and healthy volunteers, who did not normally use artificial sweeteners, for a small prospective study. The recruits consumed the maximum acceptable daily dose of artificial sweeteners for a week. Four became glucose intolerant, and their gut microbiomes shifted towards a balance already known to be associated with susceptibility to metabolic diseases, but the other three seemed to be resistant to saccharin’s effects. “This underlines the importance of personalized nutrition — not everyone is the same,” says Elinav.” Sugar substitutes linked to obesity

text article science heath obesity nas artificial sweeteners diabetes metabolic disorder glucose sweet microbiome bacteria diet food