It’s important to maintain a strong immune system within the gut that is ready to act against potential threats. However, reduced immune tolerance and overactive immune responses may lead to chronic digestive symptoms and diseases, including inflammatory bowel disease. The complex relationship between the gut microbiome and the immune system maintains the intestinal immune homeostasis.

According to a recent study published in Cell Host & Microbe, eating a Western diet can weaken the gut’s immune system in as little as 8 weeks, increasing the risk of intestinal inflammatory conditions or infections.

This study, which was conducted in both mice and humans, demonstrated that consuming a high-fat, high-sugar diet damages innate mucosal immune cells in the gut called Paneth cells. Paneth cells help regulate the gut’s immune system, but when they are dysfunctional or damaged, the gut is considerably susceptible to infection and inflammation. Impaired Paneth cell function is a hallmark feature of inflammatory bowel disease, including Crohn’s and ulcerative colitis.

The researchers’ objective was to discover the root cause of Paneth cell dysfunction by analyzing clinical data of 400 adults and assessing the function of the Paneth cells. Researchers discovered that abnormal and unhealthy Paneth cells were linked with high body mass index in both healthy adults and individuals who were diagnosed with Crohn’s disease. Healthy mice were fed a Western-style diet for 2 months, in which 40% of the calories came from fats or sugar. The mice became obese, and their Paneth cells looked abnormal when analyzed under the microscope. After consuming a healthy diet for 4 weeks, the dysfunctional Paneth cells were restored to normal.

Findings from the study also uncovered that a high-fat and high-sugar diet increased Clostridium-mediated deoxycholic acid (DCA) levels in the ileum, a secondary bile acid metabolite of gut bacteria metabolism. Increased production of DCA was shown to activate farnesoid X receptor (FXR) and type I interferon (IFN) signaling pathways. The results showed that excess FXR and type I IFN activation triggers Paneth cell defects, suggesting a mechanistic link between a Western diet that is high in fats and sugar with an impaired innate immunity and inflammation within the gut.

Dietary supplements are also a great tool to help promote healthy intestinal immune function. Curcumin has demonstrated potential anti-inflammatory and antioxidant properties that support the gastrointestinal tract and alter the intestinal microbiota that may positively impact metabolic conditions, such as obesity. Colostrum from grass-fed cows is rich in immune and growth factors, such as immunoglobulins, lactoferrin, insulin-like growth factor 1, and amino acids that support optimal immune function and intestinal health. Prebiotics, such as larch arabinogalactans, along with probiotics (specifically Lactobacillus strains) may help restore immune tolerance in the gut by influencing natural killer cell activity and reduce pro-inflammatory mediators.

As more people around the world adopt a Western-style diet, the risk of inflammatory bowel diseases and infections have increased. Educating patients on the importance of adopting an anti-inflammatory diet that is high in fiber and low in sugar, along with the utilization of dietary supplementation to support healthy immune function in the gut is critical to help reduce the increased risk of these debilitating inflammatory conditions.

By Caitlin Higgins, MS, CNS, LDN