- Decades of evidence show that regularly consuming soda is linked to poorer health outcomes.
- The latest study on the topic suggests that the negative effects may be partly mediated by the gut microbiome.
- The researchers identified nine bacterial species that appear to be important in this relationship.
A new study, which appears in
As these microbes break down food, they produce certain compounds, or metabolites. Scientists found that these chemicals were associated with an increased risk of type 2 diabetes.
Previous research has shown that people who drink large quantities of sugar-sweetened beverages are
While consumption of these beverages has declined in recent years, they were still the leading source of added sugar intake in the United States between 2017 and 2018.
The mechanism by which soda intake influences health is likely to be multifaceted. For instance, experts believe these factors all play a part:
- excessive weight gain
- insulin resistance — when cells no longer respond adequately to insulin
- inflammation
- atherogenic dyslipidemia — unhealthy levels of blood fats.
Also, the sugar in soda “might be more easily absorbed because they’re just sugar and water,” explained senior author Qibin Qi, PhD, from Albert Einstein College of Medicine, NY, in a press release.
More recently, evidence has emerged that soda consumption may alter the gut microbiome, which could contribute to diabetes risk.
According to the authors of the new study, evidence from animal studies suggests that consuming the main sugars in soda — fructose and glucose — is linked to:
- reduced gut bacteria diversity — one marker of a less healthy microbiome
- reduced levels of short-chain fatty acids (SCFAs) — these are metabolites produced by “good” gut bacteria that support overall health
- increased levels of bacterial species linked to inflammation.
Similarly, a small study on 12 females found that high-fructose syrup reduced the number of “good” bacteria that produce a SCFA called butyrate.
Other human studies have also found that sugar-sweetened beverages are associated with
Similarly, a Chinese study showed that people who drank soda had certain bacterial metabolites in their blood that are linked to poorer Health.
The latest study, however, is the first to investigate links between soda consumption, the gut microbiome, bacteria metabolites in the blood, and type 2 diabetes risk.
As Lucy McCann, MD, registered associate nutritionist and clinical academic researcher told Medical News Today: “Assessing these associations is crucial considering that the intake of sugar-swetened beverages is
In particular, the scientists accessed data from more than 16,000 Hispanic/Latino individuals in the U.S. They chose to focus on this population because they have both high soda consumption and a high prevalence of type 2 diabetes.
The researchers found that soda consumption was linked to changes in nine species of gut bacteria. For instance, four species of bacteria that produce beneficial SCFAs were reduced in number in those who drank two or more sodas per day.
The scientists also identified levels of 56 bacterial metabolites and related compounds that were linked to changes in the gut microbiome.
These compounds are associated with the metabolism of:
- glycerophospholipid — these fats are major building blocks of cell membranes, changes in whose levels appear to be linked to diabetes
- branched-chain amino acid (BCAA) — essential amino acids that may play a part in insulin resistance.
- aromatic amino acid (AAA) — Animal studies show that reducing levels of AAA alleviates diabetes symptoms
- phenylsulfate — produced when gut microbes breakdown the amino acid tyrosine, this compound is linked to diabetes-associated kidney disease.
In this study, the scientists found that compounds associated with glycerophospholipid and BCAA were linked to raised diabetes risk and poorer metabolic traits, such as higher levels of blood sugar, higher body mass index (BMI), and lower levels of “good” cholesterol.
On the other hand, increased levels of AAA derivatives and phenylsulfate were linked with better metabolic traits.
This is one of the few studies to investigate these complex relationships between gut microbes, their metabolites, and diabetes. Much more research is needed to fully understand the links, but the authors hope that, in the future, the metabolites they measured might help predict and perhaps even treat diabetes.
“Our study suggests a potential mechanism to explain why sugar-sweetened beverages are bad for your metabolism,” said Qi in the press release. “Although our findings are observational, they provide insights for potential diabetes prevention or management strategies using the gut microbiome.”
Qi also noted that these metabolites might serve as an early warning system: “We found that several microbiota-related metabolites are associated with the risk of diabetes. In other words, these metabolites may predict future diabetes.”
The team of scientists plan to continue this line of investigation by testing “whether the bacteria and metabolites can mediate or at least partially mediate the association between sugar-sweetened beverages and risk of diabetes,” Qi says.
We asked McCann to provide some healthier options to standard sodas.
“There are plenty of Healthier swaps we can make to avoid or reduce sugar-sweetend beverage consumption,” she said. “Ultimately, when it comes to drinks, water is always the Healthiest pick.”
“However, if you’re craving something fizzy, it’s better to choose options low in sugar and sweeteners, such as sparkling waters or kombucha,” McCann advised.
Because kombucha is fermented and naturally contains live microbes, it may support the health of the gut microbiome. However, it is important to look for a product that contains live microbes and no added sugars.
“It’s difficult to find an aspect of health that hasn’t been associated with the gut microbiome,” McCann told MNT — it is a fascinating topic.
However, it is almost infinitely complex: The gut microbiome varies significantly between geographical regions and between individuals — even identical twins. It fluctuates throughout the day and it can change
Each species produces a range of compounds as it metabolises food. And each of these compounds has the potential to be converted into other compounds either by other microbes or gut enzymes.
The gut microbiome still holds many mysteries, and it is likely to keep hold of them for many years to come. But watching them unfold will undoubtedly be fascinating.
