Gut Bacteria May Change Rapidly After Severe Injury

After a severe traumatic injury, the composition of a patient’s intestinal bacteria quickly changes – a phenomenon that could affect the patient’s prognosis, new research suggests.

The finding that the gut’s so-called “microbiome” experiences a depletion in the presence of some bacteria and an increase in the presence of others came from a small investigation, involving 12 critically injured adults. The patients were aged 20 to 85.

Stool samples were collected from each person three times: when they were admitted to the hospital, and then 24 and 72 hours later. The samples were compared with those from 10 other patients who had not sustained traumatic injury.

Samples taken at the time of admission were similar in both groups. But within 24 hours, differences started to show, the investigators found. By 72 hours, three types of bacteria were depleted in the traumatic injury group, relative to the non-injury group, and the levels of two other types of bacteria had risen.

“The short time-course in which such alterations occur is also notable – such relatively rapid alterations in intestinal microbiota represent a critical and previously unrecognized phenomenon that may influence clinical course and outcomes after severe trauma,” the study authors wrote in the report.

The study was published online Oct. 23 in Trauma Surgery & Acute Care Open.

The study team, lead by Dr. Benjamin Howard from the department of surgery at San Francisco General Hospital, said more research is needed to further explore the phenomenon. But the researchers added that the findings so far point to the possibility that intestinal bacterial composition could in some way be critical to patient outcomes after a traumatic injury.



Theoretically, that could ultimately point the way toward interventions – such as administering probiotic regimes – that might help improve patient outcomes after injury, the authors suggested in a journal news release.

My Take:
We have known for several years that it epithelial lining of the gut breaks down within 24 hours in severe burn victims. This is thought to be secondary to an acute folic acid deficiency created by the need to form new skin cells.

We also know that the relationship between the microbiome and the GALT (Gut Associated Lymphoid Tissue) is intimate. The GALT routinely communicates with the microbiome, sending aquired data to the thymus resulting in a primary immune response.

In reviewing the study, the bacteria that were depleted with probiotic in nature while the two varieties that increased were commensal in low numbers, but pathogenic when their numbers increase.

I suspect that this microbial shift is a response to impairment of the immune system, specifically the GALT, in response to systemic inflammation.

The Bottom Line:
While probiotic therapy in severe trauma holds great promise, we still must solve the riddle of identifying an individual’s unique micro biotic makeup prior to administration of any probiotic. This holds true for probiotic use for the general population as well. Currently, we just don’t know what probiotic is the right one for you. I suggest limiting probiotic therapy to short duration (less than a month) after antibiotics, chemotherapy or radiation therapy.


Source: October 26, 2017 National Institutes of Health