Campylobacter (C.) is the most common food-borne zoonosis in humans, which mainly manifests with watery to bloody diarrhoea. While C. jejuni is responsible for most cases of infection, C. coli is less frequently encountered. The object of the study was to prove the clinical impact of mono- and co-colonisation of C. coli and C. jejuni on weaned piglets in an infection model and to investigate the impact on transepithelial transport processes in the jejunum and caecum. At an age of eight weeks, eight pigs were infected with C. coli (ST-5777), 10 pigs with C. jejuni (ST-122), eight pigs with both strains, and 11 piglets served as control. During the four-week observation period, no clinical signs were observed. During dissection, both strains could be isolated from the jejunum and the caecum, but no alteration of the tissue could be determined histopathologically. Mono-infection with C. jejuni showed an impact on transepithelial ion transport processes of the caecum. An increase in the short circuit current (I_sc) was observed in the Ussing chamber resulting from carbachol- and forskolin-mediated Cl⁻ secretion. Therefore, we speculate that caecal colonisation of C. jejuni might affect the transport mechanisms of the intestinal mucosa without detectable inflammatory reaction.

Campylobacter (C.) spp. represent one of the most important causes for food-borne bacterial pathogen in humans worldwide. The aim of this study was to investigate metabolic requirements of two Campylobacter strains of different species based on substrate utilisation (in vitro). Based on these results, a correlation between the colonisation and the available substrates in different intestinal sections was recorded using an animal model. Campylobacter coli (ST-5777) and C. jejuni (ST-122) were used to inoculate 16 pigs, respectively, and one group of 16 pigs was used as control. The strains differed significantly in substrate utilisation - C. coli was able to metabolise various substrates (acetate, asparagine, serine, fucose, and propionate), while C. jejuni only utilised serine. Metabolomic analysis of intestinal content from different gut sections showed the presence of all previously tested metabolites, except for fucose. A significantly larger amount of glucose was found in the jejunum of those pigs infected with C. coli, while neither strain utilised it in vitro. The analysis of the intestinal contents revealed a very low proportion of Campylobacterales in the total microbiome, suggesting that the small percentage of the inoculated Campylobacter strains in the gut microflora of the animals is too low to cause differences between the control and infected groups in the composition of the metabolome. Nevertheless, knowledge of specific nutritional requirements of the pathogens combined with proof of different metabolites in the intestinal segments may provide clues about the site of colonisation in the host and improve our understanding of this zoonotic germ.

To promote sustainable biomass recycling and support food security, Tenebrio molitor (TM) larvae can serve as an eco-friendly source of food and feed. This study compared the survival, growth performance, and nutritional composition of TM larvae fed five diets. The control (CON) diet contained distillers’ dried grains with solubles (DDGS) and wheat bran (WB), while the experimental diets included 10–40% lignocellulose-rich organic products from rewetted peatlands (LPRP) replacing WB, with DDGS adjusted to maintain equivalent protein levels (about 21%). A total of 2500 larvae were divided into five replicates per treatment (100 larvae each). Survival exceeded 90% across all groups. Larvae fed the CON diet had a higher final body weight than those on the 30% and 40% LPRP diets (p < 0.05), with no significant differences among the CON and 10% and 20% LPRP groups. The feed conversion ratio (fresh matter) was significantly lower in the CON and 10% LPRP groups than in the other groups (p < 0.05). Larvae fed the 10% LPRP diet showed slightly higher crude protein content (55.8%) compared to the control group (54.8%) and the other treatment groups, whereas those fed the 30% LPRP diet had the highest numerical total amino acid content. Taken together, these results indicate that incorporating 10% LPRP with DDGS and WB provides the best overall balance between growth performance and nutritional quality for TM larvae, supporting sustainable production and circular economy goals.

Campylobacter (C.) jejuni and C. coli are common zoonotic bacteria in pigs, which typically act as asymptomatic carriers. However, the effects of Campylobacter colonisation on the porcine intestinal microbiota and metabolome remain poorly understood. This study investigated microbiome and metabolome alterations associated with co-colonisation by C. jejuni and C. coli in the different intestinal segments of pigs. Thirty-two weaned piglets were assigned to a control group and a group inoculated with C. coli ST5777/CT828 and C. jejuni ST122/CT206. Four weeks post inoculation, jejunal and caecal contents were analysed for Campylobacter counts, metabolite profiles and microbial composition. All animals remained clinically healthy. Both Campylobacter species colonised the jejunum and caecum, with higher C. coli counts in the caecum. Campylobacter-colonised pigs showed significantly altered metabolite profiles, including reduced cysteine and urea and increased glycine in the jejunum, as well as elevated 3-hydroxybutyrate levels in the caecum. In contrast, short-chain fatty acid concentrations in the caecum were unaffected by infection. Microbiota analysis revealed a significant reduction in caecal alpha diversity, whereas jejunal diversity remained unchanged. Infected pigs exhibited increased relative abundances of Lactobacillaceae and Bifidobacteriaceae and a decreased abundance of Pseudomonadota, including Enterobacteriaceae. In conclusion, Campylobacter co-colonisation induces distinct microbiome and metabolome alterations in pigs despite the absence of clinical disease. These findings highlight complex host-microbiota–pathogen interactions that may be relevant for future Campylobacter control strategies in pig production.