[Research] 2022/09/29

The gut microbiome affects the response to medical implants

The gut microbiome and antibiotic use can affect the outcomes of surgery where biomaterials are implanted, according to a new study published by Taiwanese researchers. Every year, millions of biomaterials are implanted into patients, including cosmetic and reconstructive implants, hip and knee replacements, artificial blood vessel grafts, polymer meshes.

Prof. Patrick CH Hsieh, the corresponding author said: “Our gut microbiome is formed from trillions of bacteria living inside our digestive system. These bacteria stay with us for life, responding to our lifestyle, diet and health or disease. Our research found that antibiotic use before surgery altered that microbiome, which in turn greatly affected the outcomes of several surgeries. We used mice and pigs to carry out these surgeries under highly controlled conditions and we simulated some common surgeries. We implanted silicone under the skin, we made blood vessel grafts, we simulated a hernia repair, and we even fixed bone defects. Normally the immune system will respond, causing inflammation and sending immune cells to the implant site. In all cases, we found that antibiotics before surgery reduced this host immune response.”

The researchers also confirmed their findings using ‘germ-free’ mice, which are born and raised in a sterile environment and never establish a gut microbiome. These mice had the same muted responses as antibiotic-treated mice. Using “fecal microbiota transplant” FMT from healthy animals also returned the host response to normal. Together this provided strong evidence that the gut microbiome was responsible for altering the host response to the implanted materials.

Study co-author Dr. David J. Lundy said: “This is definitely a double-edged sword. The evidence suggests that it could perhaps reduce fibrosis and other common negative effects of material implants. On the other hand, we did see signs that it may delay wound healing or increase risks of blood clots after surgery. In the future maybe we can identify the most important strains of bacteria which could help us recovery from surgery better. There’s a lot more research to be done in this field.”

The research was carried out by scientists from Academia Sinica and Taipei Medical University, Taiwan, and University of Washington Seattle, USA. Prof. Patrick CH Hsieh is a board-certified surgeon, Distinguished Research Fellow at Academia Sinica, Professor at National Taiwan University, and holds academic positions at UW Seattle and U Wisconsin Madison. The research is published in the peer-reviewed journal Biomaterials. https://doi.org/10.1016/j.biomaterials.2022.121807


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