Afm Rajibur Rahman | ALES Graduate Seminar

Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES PhD Final Exam Seminar by Afm Rajibur Rahman. This seminar is open to the general public to attend.

PhD with Dr. Ben Willing.

Thesis Topic: Impact of reintroducing lost gut microbes on intensively raised piglets.

Abstract: 

The microbiome of wild animals is believed to be co-evolved with host species, which may play an important role in host physiology. In pigs, it has been assumed that rigorous hygienic practices, in combination with antibiotics and diets with simplified formulas used in the modern swine industry, may negatively affect the establishment and development of their native microbiome. Recent studies in mice reported that the transplantation of wild mice microbiota into the laboratory mice improved their overall fitness and disease resilience. Therefore, we hypothesized that the domestic pigs have an altered gut microbial community with missing symbiotic bacteria compared to their wild counterpart. Additionally, we hypothesized that reintroducing bacteria from wild pigs into conventional pigs would allow them to colonize and beneficially influence host physiology.

In the first study, we evaluated the fecal microbiota of 90 domestic pigs sampled from 9 farms in Canada and 39 wild pigs sampled from three different locations on two continents (North America and Europe). Wild boar gut microbiota community structure differed from the domestic pigs and was enriched with complex fibre-degrading and soil-associated bacteria, while domestic pigs were enriched with phyla that harbor many potential pathogenic genera, such as Fusobacterium, Campylobacter, and Escherichia-Shigella.

Variability in donor microbial composition, viability, and the unintentional introduction of interfering agents such as viruses and fungi contribute to inconsistent outcomes in pig fecal microbiota transplantation (FMT) studies. To overcome this, we evaluated whether cultured mixed microbial communities (MMC) from a healthy sow can modulate the gut microbiota in recipient piglets, similar to FMT. We found that microbial composition was modestly altered in pigs receiving FMT compared to Control, mainly attributed to reduced inter-animal variations. Pigs receiving FMT or MMC were consistently enriched with similar ASVs and increased SCFA production in the cecum without altering the body weight or cytokine profiles.

Finally, we evaluated how MMC from wild boars (WB) colonized conventional piglets and assessed the effects on metabolite profiles and immune responses. We observed distinct microbial communities in WB-inoculated piglets compared to Controls, with trends toward differentiation from Sow but not Mix (Sow+WB) groups. Interestingly, WB-derived microbes were more successful in colonizing piglets, particularly in the Mix group, where they outcompeted sow-derived microbes. WB group cecal digesta enriched with a few Lactobacillus genera and histamine, with higher histamine levels linked to Lactobacillus abundance. Although the WB and Mix groups had lower cecal pro-inflammatory cytokine levels than the Control and Sow groups, no differences in weight gain, fecal scores, or plasma cytokines were observed.

Successful colonization of WB microbes suggests their potential to modulate gut microbiota and metabolite profiles in domestic pigs; however, further extensive research is needed to explore implications for animal welfare and performance.