Gut Microbiota Imbalance Linked to Death After Transplant
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Gut Microbiota Imbalance Linked to Death After Transplant

Gut Microbiota Imbalance Linked to Death After Transplant
Gut bacteria, microbiome. Bacteria inside the large intestine, concept, representation. 3D illustration. Gut bacteria, microbiome. Bacteria inside the large intestine, concept, representation. 3D illustration.

Research suggests that an unhealthy balance of gut microbes is associated with an increased risk of death in people who receive a donor organ. These findings add to our understanding of the gut microbiome’s connection to long-term health. Specifically, the study found an increased risk of death from cancer and infections associated with a shift away from healthy gut microbial patterns, known as gut dysbiosis.

The impact on patients was the same regardless of whether the transplanted organ was a kidney, liver, heart or lung, researchers report in the journal Bowel.

Corresponding author Dr. Johannes Björk of the University Center Groningen in the Netherlands noted that his group had previously shown that butyrate-producing bacteria disappear in transplant patients.

This short-chain fatty acid has a number of functions in the gut, including anti-inflammatory and anti-obesity effects, and helps maintain the integrity of the intestinal wall.

“The gut dysbiosis experienced by organ transplant recipients is partly caused by the use of powerful immunosuppressive drugs to prevent organ rejection, combined with the frequent use of antibiotics,” he stressed.

“While immunosuppressive drugs save lives, they are also a double-edged sword.”

The research team examined the metagenomes of 1,337 stool samples collected from 766 kidney transplant recipients, 334 liver transplant recipients, 170 lung transplant recipients, and 67 heart transplant recipients.

These were then compared with the results of 8,208 people living in the same area in northern Holland.

The average age of transplant recipients was 57, and just over half were men. On average, they had received their transplant 7.5 years earlier.

During the 6.5-year follow-up period, 162 recipients died. This included 88 kidney transplant recipients, 33 liver transplant recipients, 35 lung transplant recipients, and 6 heart transplant recipients.

Overall, 28% died from infection, 23% from cardiovascular disease, 23% from cancer and a quarter from other causes.

The researchers identified 23 species of bacteria that were associated with all-cause mortality, with both increased and decreased risk.

An abundance of four Clostridium species was associated with death from all causes, especially from infection, which also affected a large number of Hawatella Hathewayi AND viper parvula.

High level Ruminococcus gnavusbut low levels of butyrate-producing species Common caterpillar, Firmicutes CAG 83 bacteria, Eubacterium AND Faecalibacterium prausnitzi were associated with deaths from all causes, especially cancer.

Application of a machine learning algorithm allowed the discovery of a second pattern of 19 bacterial species associated with all-cause mortality.

“Our results support emerging evidence that gut dysbiosis predicts long-term survival, suggesting that therapies targeting the gut microbiome may improve patient outcomes,” the researchers concluded.