The microbiome, the community of bacteria, fungi, and viruses that live in and on the human body, has emerged as a significant area of HS research. In 2025, multiple studies examined both the skin microbiome within HS tunnels and the gut microbiome in HS patients, revealing patterns that may help explain why the disease is so difficult to treat and pointing toward new therapeutic targets.
The Skin Microbiome in HS Tunnels
A systematic review published in the International Journal of Dermatology in June 2025 examined the microbial communities found within HS tunnels and lesions. The findings confirmed that HS is associated with a polymicrobial infection environment, meaning multiple bacterial species are typically present simultaneously, predominantly anaerobic bacteria that thrive in low-oxygen environments.
This polymicrobial nature helps explain why single-antibiotic approaches often have limited effectiveness. The bacterial communities in HS tunnels form biofilms, structured communities that are significantly more resistant to antibiotics than free-floating bacteria. This is one reason why combination antibiotic regimens (such as rifampicin plus clindamycin) tend to outperform single-drug approaches.
The Gut Microbiome Connection
A July 2025 study published in PMC examined gut microbiome patterns in HS patients compared to healthy controls. The findings showed that HS patients had lower overall gut microbiome diversity and richness, with enrichment of specific bacterial species. This pattern of reduced diversity is consistent with what has been observed in other inflammatory conditions including inflammatory bowel disease and psoriasis.
A February 2026 study published in Nature added another dimension to this picture, finding that HS patients have an increased risk of irritable bowel syndrome (IBS) and that both conditions share altered gut microbiome signatures. This bidirectional relationship between gut health and skin inflammation is an active area of research.
What Does This Mean for Treatment?
The microbiome research has several practical implications for HS management. First, it supports the rationale for combination antibiotic therapy rather than monotherapy. Second, it raises the possibility that gut microbiome modulation through diet, probiotics, or targeted interventions could influence HS disease activity, though this remains an area of active investigation rather than established practice.
Third, the biofilm findings support the use of antiseptic washes (such as chlorhexidine or benzoyl peroxide washes) as adjuncts to systemic treatment, since these can disrupt surface biofilms even when systemic antibiotics cannot fully penetrate established tunnel biofilms.
The Brewer's Yeast Connection
Brewer's yeast (Saccharomyces cerevisiae) elimination has been studied as a dietary intervention for HS. Some patients report significant improvement when eliminating brewer's yeast from their diet, which is found in beer, bread made with yeast, and fermented foods. The proposed mechanism involves immune reactivity to yeast antigens, which may cross-react with skin antigens in susceptible individuals. While the evidence is primarily from uncontrolled studies, the low risk of the intervention makes it worth discussing with your care team.