CORR Insights®: Disruption of the Gut Microbiome Increases the Risk of Periprosthetic Joint Infection in Mice.

In the current study, Hernandez and colleagues [4] performed a prospective study utilizing a mouse model with a titanium tibial implant that was directly inoculated with bacteria to simulate periprosthetic joint infection (PJI). The authors found that if they disrupted the gutmicrobiotawith chronic oral antibiotics, the odds of developing PJI more than doubled that of controls. The authors also noted a blunted immune response in patients with altered gut microbiota [4]. This finding supports the idea that alterations or dysbiosis in the natural gut microbiome of a host or patient may influence the risk of PJI in patients who undergo arthroplasty. As we search to minimize the frequency of what might be the most devastating complication of total joint arthroplasty, PJI, the current study supports two hypotheses of interest. First, that the gut microbiome is linked with the immune system, and second, that alterations in the gut microbiome may influence the susceptibility of patients to joint infection. The presence and importance of the humanmicrobiome has gained increased attention in medicine within the last decade [3, 7]. The majority of the 1000 distinct microbial species in each individual are found in the gastrointestinal system [3]. As suggested by the authors of the current study, changes in the microbiome may influence distant organs and have musculoskeletal implications by several mechanisms [4]. Nutritional absorption is influenced by the gut microbiota and alterations in flora may impair the absorption of key nutrients [7]. Furthermore, malnutrition is a potential modifiable risk factor for PJI [9], raising the question as towhether this link is actually caused by alterations in the microbiome. The gut is also the largest immune organ, and thus, changes in the gut microbiome may influence the immunological response directly [3]. Several strategies in modern medicine are currently used to target of the gut microbiome and combat microbial community alterations, referred to as dysbiosis. For example, fecal transplantation has been successfully used to combat Clostridium difficile infection and inflammatory bowel disease [10]. While there is no evidence to suggest that fecal transplantation would decrease the risk of PJI, there is some preliminary evidence to suggest that modifying the gut microbiome may influence PJI in an animal model. For example, one study correlated the presence of Bacillus bacteria in the gut (which is the most common bacteria included in probiotics and can be increased through simple dietary interventions like eating Greek yogurt or drinking kombucha tea) with the absence of Staphylococcus aureus colonization in the gut and nares [7]. Given that nasal decolonization of S aureus is a widely adopted strategy for preventing PJI, modifying the gut microbiome may be a novel and viable eradication strategy, though the evidence on this topic is premature, to say the least.