Barnesiella is a genus of bacteria that resides within the human gut, part of a complex community of microbes. As an anaerobic bacterium, it is adapted to the low-oxygen environment of the large intestine. While just one component of the gut microbiome, scientific investigations have pinpointed its specific contributions to human health, including protective functions and responses to medical treatments.
Protective Roles in the Gut
One of the primary functions of Barnesiella is its contribution to the strength and integrity of the intestinal barrier. This lining of cells absorbs nutrients while preventing harmful substances from entering the bloodstream. By supporting this barrier, Barnesiella helps maintain a stable internal environment.
A significant aspect of its protective capability is its role in “colonization resistance,” where beneficial microbes prevent the overgrowth of potentially harmful ones. Barnesiella is recognized for its ability to resist vancomycin-resistant Enterococcus (VRE), a bacterium that can cause difficult-to-treat infections, particularly in hospital settings. The presence of Barnesiella makes it more difficult for VRE to establish a foothold.
This resistance is achieved by outcompeting pathogenic bacteria for resources and space. Furthermore, some studies suggest that Barnesiella contributes to an anti-inflammatory environment within the gut, which helps prevent the chronic inflammation associated with various digestive health issues.
Significance in Medical Treatments
Research has uncovered the importance of Barnesiella in modern medical therapies, particularly cancer treatment. The effectiveness of immune checkpoint inhibitors, drugs that help the immune system attack cancer cells, appears to be influenced by the gut microbiome. Studies show that patients with a higher abundance of Barnesiella intestinihominis may have a better response to these immunotherapies.
The presence of this bacterium seems to prime the immune system, making it more effective at fighting tumors. For instance, B. intestinihominis has been shown to enhance the effects of certain chemotherapy drugs by promoting the infiltration of specific immune cells into tumors.
Beyond oncology, Barnesiella is important in patients undergoing allogeneic stem cell transplants. These procedures carry a risk of graft-versus-host disease (GvHD), where the donor’s immune cells attack the recipient’s body. Research indicates that the presence of Barnesiella is associated with a lower risk of developing GvHD, as it helps maintain a balanced gut environment.
Factors Influencing Barnesiella Levels
The abundance of Barnesiella in the gut is not static and can be influenced by external factors, most notably diet. A diet rich in diverse sources of fiber is considered beneficial for the gut environment where Barnesiella thrives.
Specific plant compounds known as polyphenols have been linked to an increase in Barnesiella levels. These compounds are found in foods like pomegranates, apples, berries, and red wine. The polyphenols in these foods act as nutrients for beneficial microbes, encouraging their growth.
Conversely, broad-spectrum antibiotics can negatively affect Barnesiella populations. While necessary for treating bacterial infections, these drugs can significantly reduce the diversity of the gut microbiome, including the levels of anaerobic bacteria like Barnesiella.