Biology subjects

Kolho, K.-L.

Publications and source records attributed to Kolho, K.-L..

3 recordsLinked to original sources

bioRxiv2026

Keratin 7 protein presence in stool is indicative of active pediatric-onset inflammatory bowel disease

BackgroundInflammatory bowel disease (IBD) is associated with early structural changes in intestinal epithelial cells; however, the associated molecular alterations remain incompletely understood. The cytoskeletal protein keratin (K) 7 was recently found to be focally expressed in the colonic epithelium in IBD, while absent in the healthy colon. Here, we investigated the applicability of K7 as a noninvasive stool biomarker for pediatric IBD. MethodsIn this case-control study including adolescent patients with IBD (n=27) and healthy controls (n=15), stool lysates were analyzed by proteomics, immunoassay and qPCR to determine K7 protein and mRNA content, respectively. Additionally, stool mRNA levels of the simple epithelial keratins, K8, K18, K19 and K20, were measured. ResultsStool proteomic analysis identified focal K7 and K19 in IBD samples. Additionally, 23 differentially abundant proteins, of which 18 were higher in IBD, were identified and Gene Ontology enrichment analysis highlighted immune and inflammatory pathways. K7 specific immunoassay detected fecal K7 protein in all patients with active IBD, including both ulcerative colitis and Crohns disease, while K7 was near or below the detection limit in controls and IBD patients in remission (area under ROC curve=0.88, p<0.0001). While KRT7 mRNA levels were below the detection limit, KRT8 and KRT18 transcripts were elevated in IBD samples compared to controls (p<0.05). ConclusionsK7 protein is elevated in IBD patient stool, reflecting intestinal de novo expression and increased epithelial cell exfoliation. Fecal K7 may provide a novel, noninvasive marker for IBD diagnosis and monitoring.

cell biology↗

bioRxiv2025

Infant gut microbiota in multi-child families converges with adults without a sibling-specific signature

The human gut microbiota undergoes rapid development during early life. Sibling presence has been associated with altered infant microbiota composition and accelerated maturation, but distinguishing direct microbial transmission between siblings from confounding by maternal reproductive history (parity) remains challenging. We analysed >5,000 faecal samples from >800 mother-father-infant triads in the Finnish HELMi birth cohort to characterise microbiota patterns that could inform underlying mechanisms. While sibling presence was associated with accelerated microbiota maturation and modest compositional differences, infants who both had siblings (or both lacked siblings) were no more similar to each other than mixed pairs. Instead, infants with siblings exhibited non-specific convergence with adult microbiota profiles and contributed fewer unique genera to their family metacommunities (infant-mother-father triads). Multi-child families harboured smaller but compositionally distinct metacommunities. These patterns challenge simple models of direct sibling transmission and suggest that multiple factors associated with family structure may jointly influence infant microbiota development, though specific mechanisms remain unclear.

microbiology↗

bioRxiv2025

Associations between infant gut microbiota and the living environment

The human gut microbiota is central to health and development of the host, and early life microbiota is affected by a range of factors that can alter the infants development for years to come. The role of the external, natural environment in shaping the gut microbiota is still largely unknown. We examined how the environment surrounding the home, in terms of land use, air quality, biodiversity, and traffic and road characteristics associate with the infant gut microbiota in the first two years of life with data from 893 children from the longitudinal birth cohort HELMi. We show that the environment has a minimal overall association with the microbiota development. Air quality explained the largest degree of variation in microbiota composition, while proximity to agriculture appeared to have a similar effect as poor air quality during the first 6 months, while open grey space and agriculture had similar associations after 6 months. The results suggest that the infant gut microbiota is not strongly dependent on the external natural environment, and that the impact of the environment is mostly mediated by exposure to pollution that may affect the hosts immune system and indirectly the gut microbiota.

microbiology↗