Biliary atresia (BA) stands as the primary cause of pediatric liver transplantation, yet even after surgery to correct it, most infants ultimately develop liver failure. A new comprehensive review of emerging data now identifies the gut microbiome — the extensive collection of bacteria inhabiting the digestive system — as a decisive factor in how this devastating condition progresses. The findings indicate that infants with BA carry a severely unbalanced gut microbial community, characterized by excessive growth of harmful bacteria and a marked drop in beneficial microbes such as Bifidobacterium. These microbial disruptions appear even before surgery and strongly correlate with worse outcomes, including failure to resolve jaundice and accelerated disease advancement. The review proposes that the gut–liver axis — the bidirectional signaling pathway between the intestines and the liver — might be essential for understanding why some children experience better outcomes than others.
BA is a progressive fibro‑obliterative bile‑duct disease affecting roughly one in every 10,000 to 15,000 infants worldwide. The Kasai portoenterostomy, the standard operation, aims to restore bile flow by directly attaching the liver to the small intestine. Yet only around 60% of infants achieve sufficient bile drainage, and even among those who do, ongoing liver damage frequently persists. Despite decades of research and numerous post‑surgical treatments — including antibiotics, bile‑acid medicines, and steroids — the majority of patients still require a liver transplant by early adulthood. The gut microbiome has become a major factor in liver disorders, but its involvement in neonatal and infant liver conditions — during a time when the microbial ecosystem is still maturing — has remained mostly unstudied. Owing to these obstacles, there is an urgent requirement for thorough investigation into how the gut–liver–microbiota axis influences BA pathogenesis and clinical results.
A recently published review, appearing on January 7, 2026, in the World Journal of Pediatric Surgery, consolidates current evidence regarding the gut microbiome in BA. The work, led by Dr. Vandana Jain, analyzes microbial composition in patients before and after the Kasai procedure, identifies consistent dysbiosis patterns, and explores how these microbial disturbances may fuel disease progression through mechanisms involving bile‑acid metabolism, bacterial translocation, and immune modulation.
The review uncovers a remarkably uniform microbial fingerprint in BA across multiple studies, despite differences in patient groups and laboratory techniques. Before surgery, infants with BA show a pronounced shift in microbial makeup relative to healthy infants — with pathobionts such as Streptococcus, Enterococcus, Veillonella, Klebsiella, and Clostridium dominating, while beneficial commensals like Bifidobacterium, Faecalibacterium, and Blautia are severely depleted. This pattern persists and even intensifies after the Kasai procedure, driven not only by ongoing cholestasis but also by clinical practices such as reduced breastfeeding rates and routine use of broad‑spectrum prophylactic antibiotics, both known to suppress helpful bacteria. Importantly, the depletion of Bifidobacterium has been linked to poorer jaundice clearance, heightened liver fibrosis, and a greater risk of post‑surgical cholangitis — a serious and frequent complication that further harms the liver. The review also highlights emerging evidence that microbial metabolites, particularly short‑chain fatty acids like acetate and butyrate, may have protective roles, with butyrate showing potential anti‑fibrotic effects in experimental models. Disruptions in bile‑acid metabolism, mediated by gut bacteria via enzymes such as bile salt hydrolase, further compound the problem, creating a vicious cycle of liver injury and microbial imbalance.
“The gut microbiome is not just a bystander in BA — it appears to be an active participant in disease progression,” the authors said. “We’re seeing consistent patterns where harmful bacteria expand and beneficial ones like Bifidobacterium are lost, and these changes correlate with how well patients do after surgery. The exciting part is that the microbiome is modifiable. If we can figure out how to protect and restore a healthy microbial ecosystem in these infants, we might be able to change the trajectory of their disease.”
The findings open the door to novel therapeutic strategies for BA, a condition for which treatment options have remained scarce for decades. Approaches that modulate the microbiome — including probiotics, prebiotics, and potentially fecal microbiota transplantation — have shown promise in adult liver diseases and might be tailored for infants. Early trials using Lactobacillus rhamnosus GG have produced mixed results, indicating that strain selection, timing, and combination strategies will be crucial. The review also advocates for a re‑evaluation of current clinical routines, such as the routine administration of prophylactic antibiotics right after the Kasai procedure, which may inadvertently disturb the developing microbiome. By embedding microbiome science into clinical practice, researchers hope to improve native‑liver survival and lower the need for liver transplantation in these vulnerable infants.
References
DOI
10.1136/wjps-2025-001068
Original Source URL
https://doi.org/10.1136/wjps-2025-001068
Lucy Wang
BioDesign Research
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