The human intestine hosts diverse microbial communities that play a significant role in maintaining gut-skin homeostasis. When the relationship between gut microbiome and the immune system is impaired, subsequent effects can be triggered on the skin, potentially promoting the development of skin diseases. The mechanisms through which the gut microbiome affects skin health are still unclear. Enhancing our understanding on the connection between skin and gut microbiome is needed to find novel ways to treat human skin disorders. In this review, we systematically evaluate current data regarding microbial ecology of healthy skin and gut, diet, pre- and probiotics, and antibiotics, on gut microbiome and their effects on skin health. We discuss potential mechanisms of the gut-skin axis and the link between the gut and skin-associated diseases, such as psoriasis, atopic dermatitis, acne vulgaris, rosacea, alopecia areata, and hidradenitis suppurativa. This review will increase our understanding of the impacts of gut microbiome on skin conditions to aid in finding new medications for skin-associated diseases.

Phages are the most diversified and dominant members of the gut virobiota. They play a crucial role in shaping the structure and function of the gut microbial community and consequently the health of humans and animals. Phages are found mainly in the mucus, from where they can translocate to the intestinal organs and act as a modulator of gut microbiota. Understanding the vital role of phages in regulating the composition of intestinal microbiota and influencing human and animal health is an emerging area of research. The relevance of phages in the gut ecosystem is supported by substantial evidence, but the importance of phages in shaping the gut microbiota remains unclear. Although information regarding general phage ecology and development has accumulated, detailed knowledge on phage-gut microbe and phage-human interactions is lacking, and the information on the effects of phage therapy in humans remains ambiguous. In this review, we systematically assess the existing data on the structure and ecology of phages in the human and animal gut environments, their development, possible interaction, and subsequent impact on the gut ecosystem dynamics. We discuss the potential mechanisms of prophage activation and the subsequent modulation of gut bacteria. We also review the link between phages and the immune system to collect evidence on the effect of phages on shaping the gut microbial composition. Our review will improve understanding on the influence of phages in regulating the gut microbiota and the immune system and facilitate the development of phage-based therapies for maintaining a healthy and balanced gut microbiota.

The relationship between pigs' intestinal microbiota and growth performance is of great importance for improving piglets’ health and reducing antimicrobial use. We found that gut microbiota variation is significantly associated with growth during weaning and the early nursery period.

The weaning process represents a delicate phase for piglets, and is often characterized by lower feed intake, lower weight gain, diarrhea, and ultimately increased mortality. We aimed to determine the effects of RAC supplementation in diets on improving piglet growth and vitality, reducing post-weaning diarrhea, and enhancing gut health. In a 2 × 2 × 2 factorial experiment, we selected forty sows and their piglets. Piglets were followed until seven weeks of age. There were no significant differences found between RAC treated and control piglets until weaning (p = 0.26). However, three weeks after weaning, RAC treated piglets had higher body weight and average daily growth (ADG) than the control piglets (p = 0.003). In addition, the piglets that received RAC after weaning, irrespective of mother or prior creep feed treatment, had lower post-weaning diarrhea (PWD) and fecal myeloperoxidase (MPO) level than control piglets. Gut microbiota analysis in post-weaning piglets revealed that RAC supplementation significantly increased Lachnospiraceae_unclassified, Blautia, Butyricicoccus, Gemmiger and Holdemanella, and decreased Bacteroidales_unclassified. Overall, RAC supplementation to piglets modulated post-weaning gut microbiota, improved growth performance after weaning, reduced post-weaning diarrhea and reduced fecal myeloperoxidase levels. We therefore consider RAC to be a potential natural feed supplement to prevent enteric infections and improve growth performance in weaning piglets.

Enterotoxigenic Escherichia coli (ETEC) is a pathogen responsible for post-weaning diarrhea (PWD) in piglets, which results in economic losses in pig production. The rise of antibiotic-resistant ETEC strains together with restrictions on addition of zinc oxide in pig feed require alternative management approaches. Our research examines bacteriophage therapy as a solution to control ETEC infections in newly weaned piglets. A cocktail of phages targeting a strain of ETEC F4LT1ST2 was identified and subsequently multiplicated in laboratory. We conducted a trial including nine piglets divided into three groups. The negative control group was exposed to the phage cocktail by administration with the bedding material (saw dust) on the floor of their pen. The treatment group was exposed to the ETEC strain and to the phage cocktail, and the positive control group was exposed to the ETEC strain only. Shotgun metagenomic sequencing was performed on fecal samples to characterize bacterial and phage dynamics. Throughout a 10-day period we monitored daily the rectal temperature and the diarrheal score of piglets. Subsequently we evaluated phage and bacterial counts in fecal samples to determine phage therapy effect on gut microbiota dynamics and piglet health. The PHAGE+ETEC group showed 19.2% lower cumulative diarrhea burden ( p = 0.044) and 61.9% higher average daily gain ( p = 0.065). Rectal temperature correlated significantly with diarrhea severity (per-piglet Spearman’s ρ = 0.727, p = 0.027). Alpha diversity did not differ between treatment groups across timepoints, suggesting that phage administration did not cause major shifts in microbial diversity. Metagenomic analyses showed significant reduction of E. coli abundance in PHAGE+ETEC group compared to PHAGE groups ( p = 0.009). Consistent with these observations, plaque assay results confirmed active phage-bacteria interactions: no plaque formation was detected in the feces of the ETEC-only group, whereas the PHAGE+ETEC group showed phage replication, reaching 10 ⁶ PFU/ml. This pilot study highlights the potential of phage therapy as an alternative to antibiotics for ETEC infections in piglets. Additional research with larger pig population and longer duration is required to confirm these findings and develop optimal phage application methods for swine production.

Urinary tract infection (UTI) caused by uropathogens has put global public health at its utmost risk, especially in developing countries where people are unaware of personal hygiene and proper medication. In general, the infection frequently occurs in the urethra, bladder, and kidney, as reported by the physician. Moreover, many UTI patients whose acquired disorder from the hospital or health-care center has been addressed previously have been referred to as catheter-associated UTI (CAUTI). Meanwhile, the bacterial biofilm triggering UTI is another critical issue, mostly by catheter insertion. In most cases, the biofilm inhibits the action of antibiotics against the UTI-causing bacteria. Therefore, new therapeutic tools should be implemented to eliminate the widespread multidrug resistance (MDR) UTI-causing bacteria. Based on the facts, the present review emphasized the current status of CAUTI, its causative agent, clinical manifestation, and treatment complications. This review also delineated a model of phage therapy as a new therapeutic means against bacterial biofilm-originated UTI. The model illustrated the entire mechanism of destroying the extracellular plyometric substances of UTI-causing bacteria with several enzymatic actions produced by phage particles. This review will provide a complete outline of CAUTI for the general reader and create a positive vibe for the researchers to sort out alternative remedies against the CAUTI-causing MDR microbial agents.