Gut microbiome for disease prevention? Scientists unravel technique targeting immune cells

19 Aug 2022 --- A study conducted by Cedars-Sinai Medical Center reveals a new method to detect gut microbes that activate immune cells and help identify the cause of inflammatory diseases. Published in the Journal of Science Translational Medicine, the diseases targeted are obesity, inflammatory bowel disease, cancer, liver disease and certain neurological diseases by using a protein in the blood, the human serum.

The protein helps detect which gut microbes cross the gut barrier and have an activating effect on the immune cells throughout the body. The researchers believe this development could contribute to new methods for targeting inflammatory diseases.

“By understanding which specific microbes are crossing the gut and causing inflammation in a disease, we then can devise methods to get rid of those microbes and stop the disease,” says Ivan Vujkovic-Cvijin, senior author of the study and assistant professor at the department of Biomedical Sciences and Gastroenterology, Cedars-Sinai Medical Center.

“Microbes crossing the gut barrier usually causes inflammation and activation of the immune system, which are key features of many inflammatory diseases,” Vujkovic-Cvijin adds.

Antibodies to target immune systemThe antibodies in the human serum may act as a more efficient method to target immune cells inside and outside the gastrointestinal tract.The gut microbiome is believed to play a crucial role in the over-activation of diseases involving organs beyond the gut. The researchers explain that currently, science is lacking the tools required to identify which gut microbes drive these immune cells outside the gastrointestinal tract.

The human serum – a fluid found in the blood that contains antibodies – is described as “a more devised and accurate method to quantify immune responses against gut microbes,” the researchers say, as it allows understanding of the immune system in the gut as a whole.

Through sequencing, the researchers calculated the igG score – levels of antibodies in the blood – to see how many antibodies were present against each gut microbe.

“Bacteria can migrate out of the gut into other tissues with pleiotropic effects we have yet to understand fully. Therefore, we need new ways to assess translocation non-invasively,” says Suzanne Devkota, co-author of the study and associate professor at the Cedars-Sinai Division of Gastroenterology.

Recently, gut health has received much attention in the gut-brain axis, mental health, and digestive health. Prebiotics and probiotics are therefore receiving more attention and innovation to fill the high demand. 

Bacteria targeted
The findings indicate several bacteria targeted by the immune system found through using the technique compared to healthy controls. Some of the bacterias found were Collinsella, Bifidobacterium, Lachnospiraceae and Ruminococcaceae.

“Many of the bacteria we identified haven’t been thought of as potential causative drivers of this disease. This microbial activity is likely relevant to disease progression and may represent a viable therapeutic target,” says Vujkovic-Cvijin.

“Our approach represents a complementary tool to illuminate interactions between the host and its gut microbiota and may provide an additional method to identify microbes linked to inflammatory disease,” the study says.

Edited by Beatrice Wihlander