Graft vs Host Disease (GVHD) and the Gut Microbiome

Graft-versus-host disease (GVHD) affects patients who have had allogeneic (donor-derived) bone marrow or blood stem cell transplants. In patients with leukemias, lymphomas, or other types of bone marrow diseases, blood problems, or metabolic abnormalities, the donated cells take the place of the stem cells. This produces immune system cells and red blood cells.

The immune cells produced from the donor stem cells or injected with the stem cells “see” the recipient as non-self and attack the recipient’s organs. GVHD is a significant, even fatal, reaction that can take place. The GI tract is one of the many areas of the body that GVHD can impact. The microbial diversity in the gut is extremely rich and diverse. For the maintenance of health, the balance of various microbial communities is crucial.

The development and severity of GI GVHD influence the changes in the gut flora. To lower the risk of GVHD, patients undergoing blood cell transplants take medicines that impair immune system performance. To avoid infection, they might also take antibiotics, antivirals, and antifungals. Intestinal dysbiosis, a condition caused by intestinal preparation before the transplant and antibiotics used after the transplant, is a change in the microbial communities in the gut.

Studies & Researches

• Although anti-anaerobic antibiotic medication (metronidazole) has been linked to a decrease in acute GVHD in a number of studies, no new trials have yet been reported.
• Researchers are trying to determine whether specific bacterial populations link to both higher and lower risks of GVHD.
• Increased GVH-related mortality has been linked to low gut bacterial diversity. In one study, it was discovered that decreased overall survival and an increase in transplant-related mortality were connected. This reduces bacterial community diversity in stool after engraftment following HCT.
• Human mortality from GVHD may have decreased as a result of the Blautia bacterium species.
• Lactobacillus rhamnosus GG, a probiotic strain, was linked to decreased GVHD and increased survival in mice. Further research in humans requires to determine the effects.
• GVHD risk connects to lower levels of Firmicutes phylum bacteria.
• In persons who experienced acute GVHD, lower concentrations of the Bacteroides and Parabacteroides species were available.
• Short-chain fatty acid concentrations that are lower in GVHD patients’ stool samples may be a sign of less bacterial diversity.

What are a few things you can do to manage GVHD in terms of nutrition?

Employ safe food preparation procedures

Follow a bland, low-fiber diet if you are experiencing nausea, vomiting, or diarrhea to treat your symptoms. Eat less food that is acidic, spicy, has seeds, or has tough skin. Also, drink plenty of clear liquids. Moreover, make an effort to eat regularly throughout the day in smaller amounts. Eat less lactose.

Speak with a trained dietitian for further details

It’s crucial to regularly monitor because patients with this issue are more likely to have malnutrition, and additional dietary interventions could be necessary.

Outlook

There is undoubtedly a link between GI GVHD and gut microbiota. The ideal approach would be to maintain the microbiome balance in transplant recipients. This is difficult because of the pretreatment regimen and the requirement for antibiotics. There are not enough human studies to definitively determine the optimum strategy.

A diet low in lactose (to lower Enterococci) and high in digestible fiber (to increase AIC and short-chain fatty acid production) after a patient has recovered from GI GVHD. This may assist in maintaining a number of beneficial bacteria in the gut. Also, this helps in improving gut health and reducing the risk of this recurrence