Biology subjects

Munukka, E.

Publications and source records attributed to Munukka, E..

3 recordsLinked to original sources

bioRxiv2025

Faecal transplantation from exuberant toddlers increases exploratory behaviour in rats

BackgroundBehavioural phenotypes have previously been transferred via faecal microbiota transplantation (FMT) from patients with psychiatric disorders to rodents. Studies indicate that the gut microbiota composition may be linked to certain temperament traits, defined as biologically-based differences in emotional reactivity and self-regulation. Here, we aimed to determine if the gut microbiota plays a role in temperament using an FMT approach. We focused on the temperament traits of exuberance, defined as positive reactivity, decreased behavioural inhibition, and high behavioural approach tendencies. MethodsFaeces from 2.5-year-old toddlers from FinnBrain Birth Cohort Study with high exuberance/approach or high behavioural inhibition in the LabTAB bubbles-episode was transferred to juvenile male Sprague Dawley rats (age 22/23 days). Behaviour of the rat recipients (n=53) was assessed using the novel non-social arena, novel social arena, hole board test for exploratory behaviour, social approach-avoidance test, and forced swim test. The faecal pellets collected from the rodents were analyzed with 16s rRNA sequencing and faecal samples from the sample of toddlers (which included the donors, n=176) were analysed using short-read metagenomic sequencing. The striatum and prefrontal cortex from the rodents brains were analysed post-mortem using RNAseq. ResultsMicrobiome from toddlers with high exuberance traits induced increased exploratory behaviour compared to vehicle-controls and rats receiving faeces from inhibited toddlers. Locomotor activity, social, and depressive-like behaviour remained unaffected. We noted a downregulation of the dopamine synapse pathway within the striatum of the rats that received faeces from the inhibited trait donors compared with vehicle-controls. Faecal microbiota of rats receiving faeces from the same donor resembled more each other than rats from a different cage. Clostridium species AM29 11AC in toddler microbiome was positively related to exuberance, but there were no cross-sectional associations between faecal metabolites in the human sample. ConclusionsFMT from exuberant toddlers lead to altered exploratory-related behaviour in rats.

microbiology↗

bioRxiv2024

Fecal microbiota and metabolite composition associates with stool consistency in young children

Transit time, fluid intake, diet, and overall gut health influence stool consistency. However, the relationships between the gut metabolome (microbial metabolites) and stool consistency in infants and young children remain poorly understood. Here, we analyzed the metabolome and microbiota of 618 stool samples from children aged 2.5 months (n = 360), 6 months (n = 229), 14 months (n = 274), and 30 months (n = 169) from the FinnBrain Birth Cohort Study, and related these data to stool water content and parent-reported stool consistency. Breastfeeding showed the strongest association with both stool consistency and fecal water content. Concentrations of newly identified microbial bile acid amidates were associated with constipation and stool water content, while bile salt hydrolase, an enzyme involved in bile acid deconjugation and conjugation was predicted to be negatively associated with stool water content. In addition, short-chain fatty acids, particularly acetate, were positively associated with stool water content, whereas branched-chain short-chain fatty acids showed negative associations. These findings suggest that longer gut transit time permits more extensive microbial metabolism, including the transformation of bile acid amidates. We also found that microbial taxonomic richness, diversity, and community composition were primarily associated with stool water content, with only weak associations with stool consistency. Overall, our results highlight the importance of documenting stool consistency in fecal metabolomics and microbiome research, and provide new insights into how breastfeeding, microbial metabolism, and gut transit time shape early-life gut development.

systems biology↗

bioRxiv2023

Skin microbiota variation in Indian families

BackgroundIn Indian culture, extended families have symbolized our tradition. Families often encompass members spanning multiple generations cohabiting the same household, thereby sharing ethnicity, genetics, dietary habits, lifestyles, and living conditions. The joint or extended family setup provides an opportunity to compare variations in microbiota composition within and between families. While previous research has demonstrated that skin microbiota can be influenced by factors such as ethnicity, geography, diet, age, and sex, its associations among Indian family members that may share also genetic background remains largely unexplored. MethodsThe present study involved seventy-two individuals from fifteen families in two geographical regions of Maharashtra, India. Bacterial DNA was extracted from axillary sweat samples, followed by sequencing of V3-V4 regions of the 16S rRNA. The generated taxonomic profiles were used to quantify microbiota diversity and similarities in skin microbiota composition within and between families, taking into account factors such as genetic relatedness, diet, sex, age, geographical location, and co-habitation. ResultsThe skin microbiota composition typically comprised Firmicutes, Proteobacteria, and Actinobacteria phyla. Notably, the Shannon alpha diversity was moderately associated with dietary habits and geographical location (Kruskal-Wallis; FDR<0.1), whereas no significant differences were observed for other key factors such as age, location, or sex. A significant association was also observed between taxonomic composition and shared familial membership (p=0.001; PERMANOVA), with a borderline significant association with geographical location (p=0.07). When within and between family comparisons were investigated across three generation (G1-G2, G2-G3 and G1-G3), no significant differences were observed, however, in general skin microbiota was more similar within than between families. ConclusionThis study underscores the diversity and commonalities in skin microbiota composition within and between families. We observed that every family has a unique skin microbiota and among the various covariates, significant association was observed for diet and geographical location. Our study highlights that family relations may have specific associations with skin microbiota composition and diversity. Further studies with larger sample sizes will help to elucidate the relative contributions of shared co-habitation and genetic backgrounds.

microbiology↗