The current study aims to evaluate the potential roles of taking probiotics postoperatively in attenuating the gastrointestinal complications and disturbed gut microbiota in colorectal cancer (CRC) patients undergoing chemotherapy. One hundred eligible CRC patients who were treated with radical surgery and needed to receive chemotherapy were recruited. Half of them were randomly assigned to the Probio group to take a probiotic combination from post-operation to the end of the first chemotherapeutic course. The other half of patients taking placebo instead were classified as the Placebo group. Gastrointestinal complications such as nausea, acid reflux, abdominal pain, abdominal distention, constipation, and diarrhea were recorded during chemotherapy. Fecal samples were collected preoperatively and after the first cycle of postoperative chemotherapy for 16S rRNA high-throughput sequencing and short-chain fatty acids (SCFAs) analysis. Results showed that probiotics administration could effectively reduce chemotherapy-induced gastrointestinal complications, particularly in diarrhea (p < 0.01). Additionally, chemotherapy also reduced the bacterial diversity indexes of the gut microbiota in CRC patients, which could be significantly increased by taking probiotics. Moreover, this chemotherapy caused significant changes in the composition of the gut microbiota, as indicated by decreased phylum levels of Firmicutes and increased Bacteroidetes, Proteobacteria, and Verrucomicrobia. In particular, several bacterial genera such as Akkermansia and Clostridium were significantly increased, while Prevotella, Lactobacillus, and Roseburia were decreased (p < 0.05). However, probiotic administration could effectively restore these taxa changes both at the phylum and genus levels, and mildly increase the genus levels of Bifidobacterium, Streptococcus, and Blautia. Furthermore, probiotics could also promote the production of SCFAs, particularly increasing acetate, butyrate, and propionate (p < 0.0001). These results support the beneficial effects of the probiotic interventions as novel alternative or complementary strategies in chemoprevention.

Vaginal microbiota dysbiosis, characterized by the loss ofLactobacillusdominance and increase of microbial diversity, is closely related to gynecological diseases; thus, intervention on microbiota composition is significant and promising in the treatment of gynecological diseases. Currently, antibiotics and/or probiotics are the mainstay of treatment, which show favorable therapeutic effects but also bring problems such as drug resistance and high recurrence. In this review, we discuss the role of vaginal microbiota dysbiosis in various gynecological infectious and non-infectious diseases, as well as the current and potential interventions.

Infertility is one of the most common reproductive system diseases, and no effective method is available for its treatment. Although in vitro fertilization (IVF) has been widely used to enhance the clinical pregnancy outcome of infertility, the unsatisfied pregnancy rate with unknown reasons is obtained. To identify the possible cause of IVF failure, 555 patients were enrolled in the present study to determine their relevant clinical characteristics and vaginal microbiota. Our results indicated that the age and endometrium thickness significantly affected the pregnancy success rate of pregnant patients (P group) and non-pregnant patients (NP group) receiving IVF, and high values of luteinizing hormone, estrogen and progesterone were observed from P group. Furthermore, the Partial Least Squares Discriminant Analysis (PLS-DA) indicated a different microbial composition in P group and NP group, and a higher microbial abundance had been identified in non-pregnant patients compared with pregnant patients. At phylum level, a higher abundance of Firmicutes and Proteobacteria, and a lower abundance of Actinobacteria, Fusobacteria, and Bacteroidetes were obtained in pregnant patients compared with non-pregnant patients. At genus level, a lower abundance of the probiotic Lactobacillus, and higher abundance of pathogens Gardnerella and Prevotella were identified from non-pregnant patients. Therefore, the disordered microbiota, characterizing by the reduction of probiotics and overgrowth of pathogens in non-pregnant patients, may be used as a potential indicator for a higher IVF failure rate.

Abdominal adhesions refer to abnormal adhesions which cause a series of complications in numerous patients. In the present study, the beneficial effect of a combination of probiotics (Lactobacillus plantarum, L. acidophilus, L. rhamnosus and Bifidobacterium animalis) on abdominal adhesions in a rat model were verified. The present results indicated that probiotic treatment significantly reduced the levels of proinflammatory factors interleukin (IL)‑1β, IL‑6 and TNF‑α in serum and intestinal tissue (P<0.05), and markedly downregulated the inflammatory (TLR4/NF‑κB) and fibrotic (TGF‑β1/Smad) signalling pathways in intestinal tissue, especially in the prevention group (P<0.01). The high‑throughput sequencing results further supported that the probiotics significantly increased the relative abundance of probiotic Bacteroidetes (at the phylum level), Bacteroidales (at the order level), Lactobacillales (at the order level) and Lactobacillus (at the genus level), and markedly reduced the number of pathogenic Proteobacteria (at the phylum level), Erysipelotrichales (at the order level), Verrucomicrobiales (at the order level), Klebsiella (at the genus level) and Serratia (at the genus level). In conclusion, probiotics can effectively reduce abdominal adhesions by restoring the microbial balance and reducing inflammation and fibrosis caused by surgery.

Vulvovaginal candidiasis (VVC) is the second most common cause of vaginal infection globally after bacterial vaginosis (BV) and associated with adverse reproductive and obstetric outcomes, including preterm delivery, sexually transmitted infections and pelvic inflammatory disease. Although effective control of VVC is achievable with the use of traditional treatment strategies (i.e., antifungals), the possibility of drug intolerance, treatment failure and recurrence, as well as the appearance of antifungal-resistant Candida species remain critical challenges. Therefore, alternative therapeutic strategies against VVC are urgently required. In recent years, an improved understanding of the dysbiotic vaginal microbiota (VMB) during VVC has prompted the consideration of administering -biotics to restore the balance of the VMB within the context of VVC prevention and treatment. Here, we aim to summarize the current evidence of the anti-Candida effects of probiotics, postbiotics and synbiotics and their potential use as an alternative/complementary therapy against VVC. Additionally, this review discusses advantages and challenges associated with the application of -biotics in VVC to provide guidance for their later use. We also review new developments in VVC therapy, i.e., vaginal microbiota transplantation (VMT) as an emerging live biotherapeutic therapy against VVC and discuss existing shortcomings associated with this nascent field, expecting to stimulate further investigations for introduction of new therapies against VVC.

In the past few decades, immunotherapy has emerged as one of the most promising strategies among current treatments of cancer. In particular, the field of PD1/PD-L1 inhibitors has been boosted, widely applied into clinical practice with potent therapeutic efficacy and remarkable survival benefits on various cancers such as melanoma, non-small cell lung cancer (NSCLC), and urothelial carcinoma (UC). However, the application of PD1/PD-L1 blockade therapy is still quite restricted because of unexpected toxicities, limited response rate, as well as associated resistance. In consequence, searching for potential strategies that possibly resolve the existing limitations and enhance the therapeutic responsiveness of PD1/PD-L1 blockade is of great significance. Fortunately, the gut microbiome has been demonstrated to serve as a pivotal regulator in anti-PD1/PD-L1 therapy, providing an applicable tool to improve anti-PD1/PD-L1 clinical efficacy. In this review, we summarized published advancements about how microbiota modulated in anti-PD1/PD-L1 therapy and illustrated its underlying mechanisms, giving insights into putative manipulation of gut microbiota to facilitate PD1/PD-L1 blockade.