Beyond faecal microbiota transplantation, the non-negligible role of faecal virome or bacteriophage transplantation

Effects of fecal microbiota transplantation and fecal virome transplantation on LPS-induced intestinal injury in broilers

The interesting roles and efficiencies of fecal microbiota transplantation (FMT) have attracted considerable attention and have been gradually evidenced in specific animal models. While the growing evidence that bacteriophages play roles in FMT efficacy has attracted considerable interest. In this study, we aimed to explore the effects of FMT and fecal virome transplantation (FVT) in improving inflammatory damage and ileal microbiota disorder in broilers. A total of 224 Arbor Acres broilers were selected at 1-day-old and randomly divided into the following 4 groups, with 56 broilers in each group: the CON group (the negative control group, sterile physiological saline injection + sterile phosphate-buffered saline (PBS) solution gavage), LPS group (the positive control group, lipopolysaccharide (LPS) injection + sterile PBS solution gavage), LPS + FMT group (LPS injection + FMT solution gavage), LPS + FVT group (LPS injection + FVT solution gavage). The results showed that: LPS injection significantly upregulated the mRNA expression levels of IFN-γ (P < 0.05) and IL-8 (P < 0.001) in ileal mucosa of broilers at 11th day of age (D11), while LPS + FMT and LPS + FVT did not; LPS injection significantly upregulated the mRNA expression of ZO-1 in ileal mucosa at D11 (P < 0.01), while LPS + FMT and LPS + FVT did not; at D11, compare to CON group, LPS injection and LPS + FMT significantly increased the relative abundance of virulence factor Rab2 interacting conserved protein A-related genes in broiler ileum contents (P < 0.05), while LPS + FVT had no significant difference with CON group (P > 0.05); at D11, LPS injection significantly downregulated the biosynthesis of antibiotics pathway (P < 0.05) in the ileal contents, while LPS + FVT did not. In conclusion, both FMT and FVT could promote the recovery of inflammation caused by LPS. Furthermore, FVT had shown less disadvantage stimulation on the broilers and could reduce the risk of transmission of pathogenic genes, compared to FMT.

The gut virome is associated with stress-induced changes in behaviour and immune responses in mice

The microbiota-gut-brain axis has been shown to play an important role in the stress response, but previous work has focused primarily on the role of the bacteriome. The gut virome constitutes a major portion of the microbiome, with bacteriophages having the potential to remodel bacteriome structure and activity. Here we use a mouse model of chronic social stress, and employ 16S rRNA and whole metagenomic sequencing on faecal pellets to determine how the virome is modulated by and contributes to the effects of stress. We found that chronic stress led to behavioural, immune and bacteriome alterations in mice that were associated with changes in the bacteriophage class Caudoviricetes and unassigned viral taxa. To determine whether these changes were causally related to stress-associated behavioural or physiological outcomes, we conducted a faecal virome transplant from mice before stress and autochthonously transferred it to mice undergoing chronic social stress. The transfer of the faecal virome protected against stress-associated behaviour sequelae and restored stress-induced changes in select circulating immune cell populations, cytokine release, bacteriome alterations and gene expression in the amygdala. These data provide evidence that the virome plays a role in the modulation of the microbiota-gut-brain axis during stress, indicating that these viral populations should be considered when designing future microbiome-directed therapies.

The gut microbiota in breast cancer development and treatment: The good, the bad, and the useful!

Regardless of the global progress in early diagnosis and novel therapeutic regimens, breast carcinoma poses a devastating threat, and the advances are somewhat marred by high mortality rates. Breast cancer risk prediction models based on the known risk factors are extremely useful, but a large number of breast cancers develop in women with no/low known risk. The gut microbiome exerts a profound impact on the host health and physiology and has emerged as a pivotal frontier in breast cancer pathogenesis. Progress in metagenomic analysis has enabled the identification of specific changes in the host microbial signature. In this review, we discuss the microbial and metabolomic changes associated with breast cancer initiation and metastatic progression. We summarize the bidirectional impact of various breast cancer-related therapies on gut microbiota and vice-versa. Finally, we discuss the strategies to modulate the gut microbiota toward a more favorable state that confers anticancer effects.