FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin), a 5-fluorouracil (5-FU)-based chemotherapy regimen, is one of most common therapeutic regimens for colorectal cancer. However, intestinal mucositis is a common adverse effect for which no effective preventive strategies exist. Moreover, the efficacy and the safety of fecal microbiota transplants (FMT) in cancer patients treated with anti-neoplastic agents are still scant. We investigated the effect of FMT on FOLFOX-induced mucosal injury. BALB/c mice implanted with syngeneic CT26 colorectal adenocarcinoma cells were orally administered FMT daily during and two days after five-day injection of FOLFOX regimen for seven days. Administration of FOLFOX significantly induced marked levels of diarrhea and intestinal injury. FMT reduced the severity of diarrhea and intestinal mucositis. Additionally, the number of goblet cells and zonula occludens-1 decreased, while apoptotic and NF-κB-positive cells increased following FOLFOX treatment. The expression of toll-like receptors (TLRs), MyD88, and serum IL-6 were upregulated following FOLFOX treatment. These responses were attenuated following FMT. The disrupted fecal gut microbiota composition was also restored by FMT after FOLFOX treatment. Importantly, FMT did not cause bacteremia and safely alleviated FOLFOX-induced intestinal mucositis in colorectal cancer-bearing mice. The putative mechanism may involve the gut microbiota TLR-MyD88-NF-κB signaling pathway in mice with implanted colorectal carcinoma cells.

For chemotherapy patients, intestinal mucositis is a frequent complication. Previously, we evaluated the beneficial effect of oral probiotics in 5-Fluorouracil (5-FU) induced mucositis in BALB/c mice. Here, we used SCID/NOD mice instead to simulate the immunodeficiency of chemotherapy patients: first, to evaluate the safety of probiotic supplementation and second, to determine the probiotic effect in response to 5-FU intestinal mucositis. Thirty-six SCID/NOD mice were injected with saline (three control groups) or 5-FU (three experimental groups) intraperitoneally daily for five days. Mice were given either oral saline daily, probiotic suspension of Lactobacillus casei variety rhamnosus (Lcr35, Antibiophilus™, France) or Lactobacillus acidophilus and Bifidobacterium bifidum (LaBi, Infloran™, Italy). Blood, liver, spleen, and lymph node tissue samples were evaluated for probiotic translocation via culture and Q-PCR. Weight change, diarrhea score, jejunal villus height (VH) and crypt depth (CD), and serum cytokine levels of TNF-α, IFNγ, IL-1β, IL-6, IL-4, IL-10, IL-13, and IL-17 were also assessed. No weight loss was found in the SCID control group. Mean weight loss of 10.63 ± 0.87% was noted by day five in 5-FU group without probiotics but it was only 6.2 ± 0.43% if mice were given Lcr35 (p < 0.01) and 7.1 ± 1.80% (p < 0.01) if they were given LaBi. Diarrhea score of 5-FU group without probiotics was 2.0 ± 0.0 by day five, which dropped to 1.33 ± 0.17 (p < 0.05) and 1.42 ± 0.24 (p < 0.05) with Lcr35 and LaBi, respectively. Average VH significantly decreased and CD significantly increased in SCID mice given 5-FU. With probiotics, average CD improved (p < 0.05) while VH lengthened as well. Besides IL-13, all cytokine levels increased in 5-FU SCID mice. Both Lcr35 and LaBi significantly inhibited serum cytokines (p < 0.05). No probiotic strains were detected in blood cultures of any mice. Using SCID/NOD mice as a novel model for 5-FU induced intestinal mucositis, we find that probiotics Lcr35 and LaBi do not lead to bacteremia, can improve diarrhea and body weight, can restore jejunal crypt depth, and significantly inhibit cytokines TNF-α, IL-1β, IFNγ, IL-6, IL-4, IL-10, and IL-17.

Small for gestational age (SGA) birth is associated with high rates of mortality and morbidity in preterm infants. The aim of this preliminary observational study was to investigate the difference in gut microbiota between SGA and appropriate for gestational age (AGA) preterm infants with very low birth weight (VLBW). We included 20 VLBW preterm infants (SGA, n = 10; AGA, n = 10) in this study. Stool samples were collected on days 7, 14, and 30 after birth. We performed 16S ribosomal DNA sequencing to compare microbiota composition between both groups. The SGA group exhibited a lower abundance of Klebsiella on day 14 (SGA, 0.57%; AGA, 7.42%; p = 0.037). On day 30, the SGA group exhibited a lower abundance of Klebsiella (SGA 3.76% vs. AGA 16.05%; p = 0.07) and Enterobacter (SGA 5.09% vs. AGA 27.25%; p = 0.011) than the AGA group. Beta diversity demonstrated a separation of the bacterial community structure between both groups on day 30 (p = 0.019). The present study revealed that a distinct gut microbiota profile gradually develops in SGA preterm infants with VLBW during the early days of life. The role of changes in gut microbiota structure warrants further investigation.

Background: Maternal vitamin D deficiency (VDD) compromises fetal skeletal development. The impact of postnatal vitamin D supplementation on osteocalcin (OC) carboxylation, converting undercarboxylated (ucOC) to carboxylated osteocalcin (cOC), in offspring remains unclear, given conflicting reports on the correlation between serum 25-hydroxyvitamin D (25(OH)D) and specific OC forms. This study investigated OC profile recovery in a mouse model of maternal VDD. Methods: Female C57BL/6J mice were fed a VDD diet from four weeks pre-conception through lactation. Weaned offspring were maintained on the VDD diet and randomized to three groups: control (saline), standard-dose (1500 IU/kg), or high-dose (4500 IU/kg) vitamin D supplementation. Serum 25(OH)D, cOC, and ucOC were quantified via ELISA at 1, 2, and 4 weeks post-intervention. Results: Controls remained vitamin D-deficient (<13 ng/mL). Supplementation dose-dependently increased serum 25(OH)D (p < 0.05). Crucially, while absolute ucOC levels remained stable across all groups, supplementation significantly upregulated cOC and total osteocalcin at all time points (p < 0.05). Consequently, the ucOC/cOC ratio significantly decreased in supplemented groups. Partial correlation analysis revealed a strong positive correlation between 25(OH)D and cOC (r_partial = 0.718) and a negative correlation with the ucOC/cOC ratio (r_partial = −0.433), but no correlation with ucOC (r_partial = −0.102). Conclusions: In offspring affected by maternal VDD, vitamin D supplementation improves the osteocalcin carboxylation profile primarily by driving carboxylated osteocalcin synthesis rather than reducing the undercarboxylated pool. Serum cOC and the ucOC/cOC ratio serve as superior functional biomarkers to ucOC for monitoring therapeutic efficacy in this early-life developmental model.