Biology subjects

Collado, M. C.

Publications and source records attributed to Collado, M. C..

3 recordsLinked to original sources

bioRxiv2026

Probiotic formula intervention in infants leads to colonization and competitive strain displacement independent of IgA binding

Early-life microbiota assembly is affected by environmental exposure, diet, and immunity. We performed shotgun metagenomics sequencing of fecal samples (N=401) from a controlled infant intervention trial to evaluate how pre- and probiotic exposure affects bacterial strain dynamics, maternal-to-offspring strain transmissibility, strain persistence, and host immune responses. Species- and strain-level analyses revealed that the early-life intervention with Bifidobacterium longum subsp. infantis (BL subsp. infantis), Bifidobacterium breve, and galacto-oligosaccharides (GOS) replaced main resident strains of these species unlike breast-feeding and exclusive infant formula. BL subsp. infantis low-diversity clusters were representative of several populations and were enriched for genes linked to recombination, mobilization, and antimicrobial activity. lnterestingly, Bifidobacterium bifidum but not Bifidobacterium longum or B. breve was heavily targeted by mucosal lgA, regardless of feeding type. These findings suggest that early-life pro- and prebiotic interventions promote colonization of specific dominant strains, potentially by outcompeting and displacing existing strains, independently of host immune responses.

microbiology↗

bioRxiv2019

The Prevotella copri complex comprises four distinct clades that are underrepresented in Westernised populations

Prevotella copri is a common inhabitant of the human gut. Interest in P. copri has gathered pace due to conflicting reports on whether it is beneficial or detrimental to health. In a cross-continent meta-analysis exploiting >6,500 available metagenomes supported by new isolate sequencing and recovery of high-quality genomes from metagenomes, we obtained >1,000 P. copri genomes. This 100-fold increase over existing isolate genomes allowed the genetic and global population structure of P. copri to be explored at an unprecedented depth. We demonstrate P. copri is not a monotypic species, but encompasses four distinct clades (>10% inter-clade vs. <4% intra-clade average single nucleotide variants) for which we propose the name P. copri complex, comprising clades A, B, C and D. We show the complex is near ubiquitous in non-Westernised populations (95.4% versus 29.6% in Westernised populations), where all four clades are typically co-present within an individual (61.6% of the cases), in contrast to Westernised populations (4.6%). Genomic analysis of the complex reveals substantial and complementary functional diversity, including the potential for utilisation of complex carbohydrates, suggestive that multi-generational dietary modifications may be a driver for the reduced P. copri prevalence in Westernised populations. Analysis of ancient stool microbiomes highlights a similar pattern of P. copri presence consistent with modern non-Westernised populations, allowing us to estimate the time of clade delineation to pre-date human migratory waves out of Africa. Our analysis reveals P. copri to be far more diverse than previously appreciated and this diversity appears to be underrepresented in Western-lifestyle populations.

microbiology↗

bioRxiv2018

Can herbivore-induced volatiles protect plants by increasing the herbivores’ susceptibility to natural pathogens?

In response to insect herbivory, plants mobilize various defenses. Defense responses include the release of herbivore-induced plant volatiles (HIPVs) that can serve as signals to alert undamaged tissues and to attract natural enemies of the herbivores. It has also been shown that some HIPVs can have a direct negative impact on herbivore survival, but it is not yet understood by what mechanism. Here we tested the hypothesis that exposure to HIPVs renders insects more susceptible to natural pathogens. Exposing caterpillars of the noctuid Spodoptera exigua to indole and linalool, but not exposure to (Z)-3-hexenyl acetate increased the susceptibility to its nucleopolyhedrovirus (SeMNPV). We also found that exposure to indole, but not exposure to linalool or (Z)-3-hexenyl acetate, increased the pathogenicity of Bacillus thuringiensis. Additional experiments revealed significant changes on gut microbiota composition after forty-eight hours of larval exposure to indole. Overall, these results provide evidences that certain HIPVs can strongly enhance the susceptibility of caterpillars to pathogens, possibly through effects on the insects gut microbiota. These findings suggest a novel mechanism by which HIPVs can protect plants from herbivorous insects.

microbiology↗