This study aimed to investigate gastrointestinal tolerability, treatment persistence and iron status markers in patients with iron-deficiency anemia (IDA) who received oral iron replacement therapy (IRT) with versus without concomitant Lactobacillus plantarum 299v (L. plantarum 299v) probiotic supplementation. A total of 295 patents with newly diagnosed IDA were randomly assigned to receive either IRT alone (n=157, IRT-only group) or IRT plus L. plantarum 299v (n=138, IRT-Pro group) in this prospective randomized non-placebo-controlled study (ClinicalTrials.gov Identifier: NCT06521879). Gastrointestinal intolerance symptoms (at baseline, within the first 30 days of IRT and at any time during 3-month IRT), serum hemoglobin levels (at baseline and 3rd month of IRT) and iron status markers (at baseline and 3rd month of IRT) were recorded. IRT-Pro group, when compared to IRT-only group, experienced significantly lower rates of gastrointestinal intolerance over the course of IRT (13.0% vs. 46.5%, p<0.001) and treatment discontinuation within the first 30 days (3.6% vs. 15.9%, p<0.001). At 3rd month of therapy, IRT-Pro vs. IRT-only group had significantly higher serum levels for iron (76.0(51.0-96.0) vs. 60.0(43.0-70.0) µg/dL, p<0.001) and transferrin saturation (20.1(12.5-28.5) vs. 14.5(10.5-19.0) %, p<0.001) and higher change from baseline hemoglobin (0.9(0.3-1.3) vs. 0.4(-0.1-1.1) g/dL, p<0.001) levels. Use of L. plantarum 299v probiotic supplementation during the first 30 days of IRT in IDA patients significantly reduces the gastrointestinal burden of IRT (particularly abdominal pain and bloating), the likelihood of intolerance development (by ∼3 times) and treatment discontinuation (by∼5 times), as accompanied with improved serum hemoglobin levels and serum iron markers.

Marathon runners, subjected to intense training regimens and prolonged, exhaustive exercises, often experience a compromised immune response. Probiotic supplementation has emerged as a potential remedy to mitigate the impact of prolonged exercise on athletes. Consequently, this study sought to assess the influence of probiotic supplementation on monocyte functionality both before and after the official marathon race. Twenty-seven runners were randomly and double-blindly assigned to two groups: placebo (n 13) and probiotic (PRO) (n 14). Over 30 d, both groups received supplements – placebo sachets containing maltodextrin (5 g/d) and PRO sachets containing 1 × 1010 colony-forming unit Lactobacillus acidophilus and 1 × 1010 colony-forming unit Bifidobacterium bifidum subsp. lactis. Blood samples were collected, and immunological assays, including phagocytosis, hydrogen peroxide production, cytokine levels and monocyte immunophenotyping, were conducted at four different intervals: baseline (start of supplementation/30 d pre-marathon), 24 h-before (1 d pre-marathon), 1 h-after (1 h post-marathon) and 5 d-after (5 d post-marathon). Monocyte populations remained consistent throughout the study. A notable increase in phagocytosis was observed in the PRO group after 30 d of supplementation. Upon lipopolysaccharide stimulation, both PRO and placebo groups exhibited decreased IL-8 production. However, after the marathon race, IL-15 stimulation demonstrated increased levels of 5 d-after, while IL-1-β, IL-8, IL-10, IL-15 and TNF-α varied across different intervals, specifically within the PRO group. Probiotic supplementation notably enhanced the phagocytic capacity of monocytes. However, these effects were not sustained post-marathon.

Probiotics are being used increasingly in pregnant women, whereas the efficiency on pregnancy outcomes is yet lacking. PubMed, Embase and the Cochrane Library were searched. Relative risks (RR) or weighted mean differences (WMD) with 95 % CI were employed to calculate the summary outcomes. A total of eighteen randomised controlled trials (RCT) including 4356 pregnant women were eligible. The summary RR indicated that probiotic supplementation was associated with a significant decrease in the risk of atopic eczema (RR 0·68; 95 % CI 0·58, 0·81; P < 0·001) and eczema (RR 0·79; 95 % CI 0·68, 0·91; P = 0·002) without significant heterogeneity. Probiotic supplementation was associated with a prolonged gestational age (WMD 0·09; 95 % CI 0·04, 0·15; P = 0·001) with insignificant heterogeneity, whereas no significant effect was exerted on birth weight (P = 0·851). The risks of death (RR 0·34; 95 % CI 0·13, 0·91; P = 0·031) and necrotising enterocolitis (NEC) (RR 0·38; 95 % CI 0·18, 0·81; P = 0·012) were significantly reduced in pregnant women receiving probiotics without evidence of heterogeneity. These findings suggested that probiotics in pregnant women were beneficial for atopic eczema, eczema, gestational age, death and NEC.

Probiotics in human milk are a very recent field of research, as the existence of the human milk microbiome was discovered only about a decade ago. Current research is focusing on bacterial diversity and the influence of the maternal environment as well as the mode of delivery on human milk microbiota, the pathways of bacterial transfer to milk ducts, possible benefits of specific bacterial strains for the treatment of mastitis in mothers, and disease prevention in children. Recent advances in the assessment of early host–microbe interactions suggest that early colonisation may have an impact on later health. This review article summarises a scientific workshop on probiotics in human milk and their implications for infant health as well as future perspectives for infant feeding.