The gut microbiome has garnered significant attention for its crucial role in digestive health. It helps break down food and produce vital nutrients, influencing conditions like irritable bowel syndrome (IBS), irritable bowel disease (IBD), and leaky gut syndrome. Recent research suggests that a balanced microbiome is essential for a healthy digestive system, and that different foods can positively or negatively affect its composition.
Dairy products, including milk and cheese, have long been debated for their impact on gut health. A recent study by Dr. Li Jiao and her team, published in Nutrients, provides new insights into how these common dairy items affect gut bacteria differently. The findings suggest that milk may support a healthy gut microbiome, while cheese could potentially hinder it.
Why Dairy’s Impact on Gut Health Matters
The study analyzed the gut health of 34 individuals who had a scheduled colonoscopy between 2013 and 2017. Exclusions included participants with a history of colon diseases, inflammatory bowel disease, or other conditions that could skew the results. Researchers focused on how the consumption of milk, cheese, yogurt, and total dairy impacted the gut microbiome.
The goal was to explore whether fermented dairy products like cheese and yogurt affect gut health differently than milk. Previous studies have been inconclusive, and Jiao’s team aimed to clarify this relationship and provide biological evidence of how these dairy products might influence gut bacteria.
The Role of Milk in Promoting Gut Health
Researchers discovered that participants who consumed more milk and total dairy had higher microbial diversity in their gut microbiome. Diversity is considered a key factor in maintaining gut health and stability, making the microbiome more resilient to external disturbances like infections or dietary changes. The study found that a higher alpha-microbial diversity was associated with a more balanced gut microbiota, which in turn is linked to better overall health.
More specifically, those who drank more milk showed increased levels of beneficial bacteria, such as Faecalibacterium and Akkermansia. These bacteria are vital for reducing inflammation and promoting a healthy gut lining, and they may help prevent chronic conditions like obesity and type 2 diabetes. Additionally, Akkermansia has been shown to play a role in protecting against conditions like IBD.
For individuals who are not lactose intolerant, consuming low-fat dairy may further support the growth of these beneficial bacteria. Those who are lactose intolerant may opt for alternatives like yogurt or lactose-free dairy, which also provide similar benefits.
The Negative Effects of Cheese on Gut Health
On the flip side, the study found that participants who consumed higher amounts of cheese had lower levels of Bacteroides in their gut microbiome. This bacterium is typically beneficial for gut health, aiding in digestion and nutrient absorption. However, research on Bacteroides has produced conflicting results, as some strains have been linked to harmful effects, including the promotion of tumor formation and the development of colorectal cancer. Lower levels of Bacteroides have also been associated with IBD.
The reduced presence of Bacteroides among cheese consumers may be due to the types of bacteria present in different cheeses, as well as the fermentation process. Furthermore, higher cheese consumption correlated with lower gut microbiome diversity, suggesting that too much cheese may diminish gut health over time.
Why This Research Matters
Dr. Jiao’s research emphasizes the complex relationship between dairy products and gut health. While milk appears to have a positive effect on the microbiome by promoting the growth of beneficial bacteria, cheese may hinder gut health by reducing the abundance of key bacteria like Bacteroides. This difference may be attributed to the distinct fermentation processes involved in producing these dairy products.
For people with gastrointestinal issues such as IBD, Dr. Rudolph Bedford, a gastroenterologist, suggests that milk might be a better option for supporting gut health, while cheese consumption should be limited. However, he stresses the need for more research to determine which types of cheese are most harmful to gut health and whether the processing of cheese plays a significant role in these effects.
