The microgel protects the “good” bacteria in the intestines and removes the harmful ones

Probiotics are live microorganisms that, when taken in the right amounts, can help maintain a healthy gut microbiome. They can restore the population of “good bacteria” after intensive antibiotic therapy. They can also be used to treat certain bowel diseases, such as Crohn’s disease.

The microbiome is a group of microbes inhabiting the human body, which reaches its greatest diversity in the gut.

Researchers at China’s Zhengzhou University have developed a microgel probiotic delivery system that keeps ‘good’ bacteria safe while actively removing ‘bad’ ones. During experiments on mice, it was able to cure enteritis without side effects.

There is a delicate balance of bacterial populations in the digestive system. When this balance is disturbed, harmful bacteria can cause intestinal inflammation, which requires expensive and non-selective immunosuppressants to treat. This sometimes results in strains of bacteria that are resistant to antibiotics. An alternative strategy is to restore the disturbed balance by providing probiotics. But in order to reach the large intestine, the beneficial bacteria must first pass through the stomach acid, reach the large intestine and win a “competition” there with numerous invasive bacteria. The probiotic delivery systems used so far simply protect them from being digested. Chinese scientists – Zhenzhong Zhang, Junjie Liu, Jinjin Shi and their colleagues wanted to combine probiotics with specialized microgel beads that can not only protect good bacteria, but also actively help remove harmful ones. Researchers combined sodium alginate and calcium tungstate nanoparticles into small, microgel beads, then coated them with beneficial probiotic bacteria. The gel protected the bacteria from the deadly effects of stomach acid and extended their stay in the large intestine. There, specific proteins whose expression (the process by which the information contained in the genes is decoded, read and translated) is particularly intensified in inflammation of the intestines, bound to calcium, releasing tungsten. Tungsten, in turn, displaced another metal – molybdenum – from the key enzyme substrate of ‘bad’ bacteria Enterobacteriaceaewithout harming the probiotic bacteria. During experiments in a mouse model of colitis, it was possible to increase the level of probiotic bacteria in the colon without side effects. The scientists published the results of their research in an article that appeared on June 21 in the journal “ACS Central Science”. Mice that were given the probiotic with the help of microgel beads did not show many of the characteristics of colitis, such as shortening of the colon or damage to the intestinal barrier. This suggests that such a delivery system may be a viable treatment strategy. The authors of the study want to prove its usefulness in more advanced preclinical models.