However, Bifidobacteriaceae are capable of binding iron in the large intestine, thereby limiting the formation of free radicals synthesized in the presence of iron, and thus reducing the risk of colorectal cancer. Animal studies have revealed that supplementation with probiotics, prebiotics and synbiotics has a significant effect on bone calcium, phosphate and bone metabolism. The dynamic interaction between microbiota and zinc was shown. Human studies have provided evidence of the influence of probiotic bacteria on parathormone, calcium and phosphate levels and thus on bone resorption. Recent studies have produced new information mainly on the impact of the intestinal bacteria on the metabolism of calcium and iron. From a scientific perspective, the most urgent fields that remain to be investigated are the identification of all human gut microbes and new therapies targeting the interaction between intestinal bacteria and minerals.

Association between the gut microbiota and mineral metabolism. [2018]

In this post, I will try finding the studies and further information.

• A Systematic Review and Meta-Analysis on the Effects of Probiotic Species on Iron Absorption and Iron Status.[2019] “Lactobacillusplantarum 299v  significantly improved iron absorption in humans. ” i.e. Jarrow Formulas Ideal Bowel Support 299v
• Enhancement in Iron Absorption on Intake of Chemometrically Optimized Ratio of Probiotic Strain Lactobacillus plantarum 299v with Iron Supplement Pearl Millet. [2019]
• Identification of the key excreted molecule by Lactobacillus fermentum related to host iron absorption. [2017] – Increases iron
• Probiotic strain Lactobacillus plantarum 299v increases iron absorption from an iron-supplemented fruit drink: a double-isotope cross-over single-blind study in women of reproductive age. [2015]
• Fecal total iron concentration is inversely associated with fecal Lactobacillus in preschool children. [2017] — so specific lactobacillus species may determine increase or decrease of Iron
• Probiotics Lactobacillus reuteri DSM 17938 and Lactobacillus casei CRL 431 modestly increase growth, but not iron and zinc status, among Indonesian children aged 1-6 years. [2013]
• Effects of a Multispecies Probiotic Supplement on Bone Health in Osteopenic Postmenopausal Women: A Randomized, Double-blind, Controlled Trial. 2017 Increase of calcium from probiotic containing: Lactobacillus rhamnosus, Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus acidophilus, Bifidobacterium breve , Bifidobacterium longum, Streptococcus thermophilus

• The Effect of Multispecies Probiotic Supplementation on Iron Status in Rats.[2019] Serum Fe was lower in probiotic groups
• Effect of probiotics on the basis of Bacillus subtilis and Bifidobacterium longum on the biochemical parameters of the animal organism.[2018] ”  At the end of the experiment, the content of calcium in the body tissues of animals of group (Bifidobacterium longum)  exceeded this indicator in group (Bacillus subtilis 534) by 3.9%, phosphorus by 17.6%, copper by 28.5%, and zinc by 15.2%.  “
• Probiotics Lactobacillus reuteri DSM 17938 and Lactobacillus casei CRL 431 modestly increase growth, but not iron and zinc status, among Indonesian children aged 1-6 years. [2013]
• The probiotic bacterial strain Lactobacillus fermentum D3 increases in vitro the bioavailability of Ca, P, and Zn in fermented goat milk.[2013]
• Influence of Bifidobacterium bifidum on release of minerals from bread with differing bran content. [2012] ” Bifidobacterium bifidum KD6 enhanced amounts of magnesium and zinc released from all types of bread, while manganese and copper rose only from white bread with 15% bran addition. Bacteria decreased amounts of calcium and iron released from bread. “
• Bifidobacterium dentium Fortifies the Intestinal Mucus Layer via Autophagy and Calcium Signaling Pathways. [2019] ” We also identified that B. dentium-secreted products, such as γ-aminobutyric acid (GABA), stimulated autophagy-mediated calcium signaling and MUC2 release “
• ” that arsenic and mercury were significantly associated with Parabacteroides and Oscillospira in the gut. ” [2019]

Bottom Line

The available literature suggests that Lactobacillus and Bifidobacterium are dominate player for calcium levels. Since these are much higher in children than adults, this would assist in bone growth by providing the needed calcium. This appears to extend to other minerals such as zinc, copper, phosphorus in a similar manner.

Both Lactobacillus and Bifidobacterium decrease with old age and may account for calcium /bone loss issues. ” The presence of the Bifidobacterium, Faecalibacterium, Bacteroides group, and Clostridium cluster XIVa decreased with age up to 66-80 years of age,  “[2019]

Low levels of one of more of theses would hint towards insufficient of these, or a bad balance with them. High levels of one or more would hint towards a surplus of these, or a bad balance with them.