The Association of Gut Microbiota and Complications in Gastrointestinal-Cancer Therapies

Abstract

The therapy of gastrointestinal carcinomas includes surgery, chemo- or immunotherapy, and radiation with diverse complications such as surgical-site infection and enteritis. In recent years, the microbiome’s influence on different diseases and complications has been studied in more detail using methods such as next-generation sequencing. Due to the relatively simple collectivisation, the gut microbiome is the best-studied so far. While certain bacteria are sometimes associated with one particular complication, it is often just the loss of alpha diversity linked together. Among others, a strong influence of Fusobacterium nucleatum on the effectiveness of chemotherapies is demonstrated. External factors such as diet or specific medications can also predispose to dysbiosis and lead to complications. In addition, there are attempts to treat developed dysbiosis, such as faecal microbiota transplant or probiotics. In the future, the underlying microbiome should be investigated in more detail for a better understanding of the precipitating factors of a complication with specific therapeutic options.

Effect of preoperative immunonutrition on fecal microbiota in colon cancer patients: a secondary analysis of a randomized controlled trial

“…Although we did not show any statistical significance, some previous studies reported important changes in the composition of the intestinal microbiota after undergoing colorectal surgery [ 5 ]. A previous study showed that reduced alpha diversity was associated with the incidence of postoperative complications [ 23 ].…”

“…A previous study showed that reduced alpha diversity was associated with the incidence of postoperative complications [ 23 ]. A higher abundance of specific bacteria, such as Bacteroidaceae , Bifidobacterium genus, and Enterococcus faecalis, may be associated with an increased risk of anastomotic leakage [ 2 5 24 ]. In addition, the Firmicutes / Bacteroidetes ratio can be altered during colorectal cancer surgery, which may represent dysbiosis of the intestinal microbiota and can be associated with poor outcomes [ 5 ].…”

“…A higher abundance of specific bacteria, such as Bacteroidaceae , Bifidobacterium genus, and Enterococcus faecalis, may be associated with an increased risk of anastomotic leakage [ 2 5 24 ]. In addition, the Firmicutes / Bacteroidetes ratio can be altered during colorectal cancer surgery, which may represent dysbiosis of the intestinal microbiota and can be associated with poor outcomes [ 5 ]. Hence, further large-scale studies are warranted to investigate the effect of immunonutrition on the outcomes of colorectal cancer surgery.…”

“…As a result, the abundance and function of microbiota would decrease during admission [ 2 ], which could affect the outcomes of colorectal surgery. Previous studies reported that the incidence of postoperative complications, such as postoperative ileus, adhesions, surgical site infections, and anastomotic leakage, is affected by the gut microbiota [ 3 4 5 ]. Therefore, maintaining microbial homeostasis is extremely important during colorectal surgery.…”

Microbiota, Oxidative Stress, and Skin Cancer: An Unexpected Triangle

“…The link between microbial dysbiosis, chronic inflammation, immune evasion and oxidative stress has already been reported for Helicobacter pylori in gastric tumors and for F. nucleatum in CRC [ 99 , 100 ]. Despite the bond between skin microbiota, ROS and NMSC occurrence is still largely unknown, the state of dysbiosis, which causes a greater susceptibility to exogenous and non-exogenous stimuli, also favors DNA damage, such as the formation of thymine dimers and C-T transitions, erythema, immunosuppression, melanogenesis, photo-ageing and cancer [ 101 , 102 ].…”