A multi-member European research group has proposed a mechanism whereby probiotics can have a beneficial effect on a range of diseases, including obesity and diabetes, necrotising enterocolitis, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and possibly allergy. They cite evidence that probiotics can stabilise a person’s intestinal barrier integrity. Many diseases are characterised by ‘leaky gut syndrome’, including those described above, as well as chronic kidney disease.

The study was published on line in the British Journal of Nutrition on the 19^th January 2017 (DOI: https://doi.org/10.1017/S0007114516004037)

In our intestinal tract, only a single layer of cells (called epithelial, or skin cells) forms the physical barrier between the intestinal contents and the underlying blood vessels and immune system. Therefore it is essential to health and well-being that this intestinal barrier is maintained. There are a number of systems that are designed to preserve the barrier integrity including secretion of mucus, antibodies and other proteins by the epithelial cells. In addition, the epithelial cells grip each other tightly using structures called “epithelial tight junctions” that stop bacteria and toxins getting through the barrier, between the cells. Also, the body’s “good” bacteria provide a defence against “bad” or pathogenic bacteria getting to the epithelial cells that form the barrier, and attacking them. When these systems fail, however, the barrier stops being effective, and toxins, pathogens and other undesirable chemicals and molecules can pass from the gut into the surrounding tissues and blood vessels, stimulating an inflammatory response and leading to a disturbance of the body’s immune system and functions. Therefore leaky gut syndrome underlies many diseases.

The authors reviewed a number of clinical and pre-clinical studies and concluded that, “a variety of studies imply that mucosal barrier function can be improved by probiotic treatment,” and therefore could have a beneficial impact on many diseases such as diabetes, obesity, IBS, IBD and possibly allergy (and others) that have as their underlying cause a faulty intestinal epithelial barrier. They called for more clinical studies in disease populations specifically looking for markers of improvement in epithelial barrier integrity.

This study adds to the growing body of knowledge regarding the potential wide- ranging health benefits of consuming clinically tested probiotics that show health benefits. But, the authors caution, not all probiotics work, or work the same way.

References:

• Bron PA, Kleerebezem M, Brummer R-J, Cani PD. “Can probiotics modulate human disease by impacting intestinal barrier function?” Br J Nutr 2017; 19:1-15.
• Evenepoel P, Poesen R, Meijers B. The gut-kidney axis. Pediatr Nephrol 2016; doi: 10.1007/s00467-016-3527-x