- Recent research has highlighted the influence of certain foods on gut health and their potential impact on overall health.
- One study found that a byproduct of fiber digestion by gut bacteria may help to reduce colorectal cancer risk.
- Another piece of research suggests that drinking milk may increase beneficial gut bacteria, while consuming cheese may lower levels of bacteria that support gut health.
- A third study indicates that food quality and diversity have a greater impact on the gut microbiome, rather than following specific dietary plans.
The gut microbiome refers to the ecosystem of microbes that live in the intestines and play an important role in overall health. For example, the gut microbiome supports digestive health and can also influence the immune system.
Previous research notes that an imbalance in the gut microbiome can impact the development of a variety of health issues, such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), cardiovascular disease, obesity, type 2 diabetes, and depression.
The food that people consume can have a profound effect on shaping their gut microbiome. Typically, an individual can make appropriate lifestyle and dietary changes to improve their gut health and support overall well-being. However, certain foods may offer more benefits than others.
Medical News Today looks at three recent studies we have covered to offer an overview on the role of the gut microbiome and how consuming certain food products may support health.
A majority of adults in the United States do not consume enough dietary fiber. This refers to the part of plant foods that humans cannot digest, which may help to lower the risk of developing various conditions.
However, not only can the gut microbiome digest dietary fiber, it can also produce beneficial metabolites.
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When the gut microbiome breaks down plant fiber it produces molecules known as short-chain fatty acids (SCFAs), notably proprionate and butyrate. Previous research suggests that these molecules may possess anticancer properties.
In the 2025 study, laboratory experiments on human colon cells (both healthy and cancerous) and in mice, propionate and butyrate were able to alter genes that regulate the differentiation and multiplication of cells, as well as genes controlling programmed cell death.
Şebnem Ünlüişler, genetic engineer and Chief Longevity Officer at the London Regenerative Institute, who was not involved in the study, explained to MNT:
“The research focuses on short-chain fatty acids (SCFAs) like propionate and butyrate, which are produced when gut bacteria break down dietary fiber. These SCFAs can influence the activity of both cancer-promoting (proto-oncogenes) and cancer-suppressing (tumor-suppressor) genes by modifying histones, the proteins that help package DNA. By making the DNA more accessible, SCFAs can turn certain genes on or off, depending on the cell type and conditions.”
The research has shown that butyrate inhibits enzymes known as histone deacetylases (HDACs), which can result in changes that slow tumor cell growth or even trigger their death.
These findings could offer an explanation for the link between high-fiber diets and a lower risk of colorectal cancer.
However, while it is still advisable to eat plenty of fiber-rich foods, it is important to note that this was a cell-and animal-based study. More research is still necessary to determine if these results are reproducible in human trials.
Dairy products, such as milk and cheese, are rich in nutrients and can help promote bone health. They can also influence gut health. However, not all dairy products may provide the same benefits.
A study published in the journal Nutrients provides evidence that different types of dairy products have varying effects on the gut microbiome.
The research suggests that drinking more milk correlates with an increase in two types of bacteria that may support gut health, while consuming more cheese is linked to lower amounts of a third beneficial type of bacteria.
Researchers analyzed colon tissue biopsies from 34 adult participants and compared these with self-reported dairy consumption questionnaires over the past year.
Using 16S ribosomal Ribonucleic acid (rRNA) gene sequencing on 97 colonic mucosal biopsies, they found that those who consumed more total dairy and milk, and ate less cheese, appeared to have a higher alpha-microbial diversity.
Li Jiao, MD, MS, PhD, associate professor in the Department of Medicine-Gastroenterology at Baylor College of Medicine and senior author of the study, told MNT:
“The variety of species plays a crucial role in maintaining the overall Health and stability of the ecosystem. Having higher alpha-diversity in the gut means a Healthier and more balanced gut microbiota community.”
In particular, milk drinkers displayed increased levels of Faecalibacterium and Akkermansia, which relate to gut barrier integrity, anti-inflammation, and a potentially lower risk of conditions such as IBD.
Conversely, participants who ate higher amounts of cheese had a lower diversity of gut bacteria and lower amount of the bacterium
However, some species of Bacteroides can have both beneficial and harmful effects. Therefore, interpreting the results is not straightforward.
The findings suggest that milk may support a Healthier, more diverse gut microbiome, while cheese might have the opposite effect. However, it is important to note the small sample size, self-reported data, and predominantly older male cohort in the study. More research is necessary before issuing broad dietary guidance.
Previous research has highlighted that the food people consume is one of the most significant influences on the gut microbiome.
A large-scale study of over 21,000 people in the U.S., U.K. and Italy, published in Nature Microbiology, suggests that the quality and diversity of the diet — rather than the dietary pattern itself — has the biggest impact on the structure of the gut microbiome.
For this study, researchers analyzed the gut microbiomes of individuals following vegan, vegetarian, or omnivorous diets.
Omnivore dietary patterns generally showed greater overall bacterial diversity, but also had higher abundances of bacteria associated with meat digestion and conditions like IBD and colorectal cancer. However, the presence of these bacteria does not necessarily mean a person will develop disease.
By contrast, vegan and vegetarian dietary patterns typically had higher levels of gut microbes linked with fiber fermentation, especially bacteria that produce SCFAs.
However, the research notes that people following an omnivorous eating plan that consumed plenty of diverse, high-fiber plant foods, such as fiber-rich vegetables and whole grains, also had elevated levels of beneficial microbes, comparable to those seen in vegan and vegetarian dietary patterns.
Nicola Segata, PhD, professor and principal investigator at the Department of Cellular, Computational, and Integrative Biology (CIBIO) at Università di Trento in Italy, is the senior author of the study.
Segata is also on the advisory board and a consultant for the personalized nutrition program company ZOE Limited, who partly funded the research.
He explained that:
“The greater the variety of plant-based foods we consume, the greater the diversity of beneficial microbes in our gut. This is because different plant-based foods contain different types of fiber, and each fiber can stimulate the growth of different types of Health-promoting microbes. These microbes work together to improve our gut Health, so the more diversity of Health-associated microbes in our gut microbiome, the better our chances of good gut Health.”
