Lactobacillus Fermentum ME-3.

This strain is characterised by a complete glutathione system, synthesising and recycling glutathione rather than only tolerating it. Supplying glutathione and the strain addresses the same redox pool from two directions.

Cysteine availability is the limiting step in glutathione synthesis, and NAC supplies it. Since this strain's defining feature is glutathione production, precursor supply sits directly upstream of what it does.

Glutathione peroxidase is a selenoenzyme, so selenium status sets how fast reduced glutathione can be used to handle peroxides. The pairing supplies both the substrate side and the enzyme side of one reaction.

Dihydrolipoic acid regenerates oxidised glutathione back to its reduced form, keeping the pool this strain contributes to in the usable state. Recycling and production sit on the same cycle.

Ascorbate and glutathione regenerate one another in the classic recycling network, so each spares the other. A glutathione-producing strain feeds into the same loop.

Alpha-tocopherol stops lipid radical chains in membranes and is regenerated by ascorbate and glutathione. The strain's glutathione output supports the far end of that regeneration chain.

Chicory fructans provide a carbon source lactobacilli ferment, supporting the delivered strain in the colon. Strain with substrate is standard synbiotic practice.

Short fructans ferment early in the colon and are readily used by lactic acid bacteria. The acidification that follows favours the delivered strain.

Lactate and acetate from lactobacilli are consumed by bifidobacteria and butyrate producers, so the genera feed one another. Multi-genus formulation rests on this.

Charcoal adsorbs luminal organic material broadly, including the substrate and metabolites the strain works with. Separate the two by several hours.

Silver ions act on bacterial membranes and thiol enzymes without distinguishing genera, which includes a delivered lactobacillus. It also consumes thiols, working against the redox point of this strain.

Recycling oxidised glutathione back to its reduced form runs through glutathione reductase, and that enzyme carries FAD built from riboflavin. Riboflavin status therefore sets a ceiling on how fast the recycling step can turn over, whatever the bacterial contribution is. This is cofactor biochemistry rather than a tested combination.

Glutathione is a tripeptide of glutamate, cysteine and glycine, and cysteine availability is the step that normally limits how much gets made. Supplying cysteine addresses the substrate side of the same pathway this strain is described as touching. No combination trial is implied.

Glutathione synthetase joins glycine onto gamma-glutamylcysteine in the second and final synthesis step. Glycine is rarely scarce in a mixed diet, so its role is to complete the substrate set rather than to drive the pathway. Textbook biochemistry, not a measured pairing.

Methionine feeds homocysteine, which the transsulfuration route converts to cystathionine and then cysteine. That makes methionine an indirect upstream supply for glutathione synthesis. The connection is pathway chemistry and says nothing about dose.

Both transsulfuration enzymes need pyridoxal 5-phosphate, so B6 status governs how much cysteine reaches glutathione synthesis. When B6 is low, homocysteine accumulates upstream instead of converting. A cofactor relationship, not a trial result.

Glutaminase converts glutamine to glutamate, the first residue that gamma-glutamylcysteine synthetase uses. Glutamine is also the dominant fuel of the enterocytes where a colonising strain sits. Both links are pathway-level rather than outcome-level.

Superoxide dismutase hands hydrogen peroxide to the glutathione peroxidase step, so zinc sits one node upstream in the same handling network. Adding zinc changes the network's capacity, not the strain's behaviour. This is a mechanistic pairing and no human co-administration study is cited for it.

Galactooligosaccharides pass the small intestine intact and are fermented by lactobacilli and bifidobacteria in the colon. Co-dosing a fermentable substrate with a live strain is standard synbiotic practice. Whether it changes any measured endpoint for this particular strain has not been shown in the papers available here.

Resistant starch escapes amylase digestion and is fermented distally, shifting the substrate pool a delivered strain lands in. The pairing is a formulation logic rather than a measured combination for this strain.

Partially hydrolysed guar gum ferments gradually along the colon and is tolerated at doses where intact gums are not. It provides substrate without the viscosity load of the parent gum. No study here pairs it with this strain.

Pectin is fermented by mixed colonic communities to short-chain fatty acids. Its use alongside a live strain is plausible substrate support and nothing more specific.

Oat beta-glucan reaches the colon and is fermented there, contributing to the substrate pool available to lactic acid bacteria. The pairing is mechanistic, with no strain-specific data in the papers listed.

Multi-strain lactobacillus blends are the ordinary commercial format, and co-formulated strains occupy overlapping niches without displacing one another at typical doses. A blend's effect is not the sum of its strains, so the honest framing is co-administration rather than amplification.

L. plantarum is acid and bile tolerant and is routinely blended with other lactobacilli. Co-administration is well established as a format; strain-level interaction with ME-3 has not been measured in the sources available.

Lactobacillus and bifidobacterium species ferment different substrate fractions and are conventionally paired for that reason. The pairing broadens the fermentation profile of a product rather than boosting one strain.

S. boulardii is a yeast, so it neither competes for the same carbohydrate transporters nor shares bacterial susceptibilities. That separation is why the two are often taken together. Co-administration is the claim here, not an added effect.

Lactobacilli produce lactate and acetate, which butyrate-producing colonic species take up and convert onward. Supplemental butyrate supplies the end product directly instead of relying on that hand-off. The cross-feeding step is established; the combined effect on any endpoint is not measured here.

Lactoferrin sequesters free iron, which shapes which gut organisms can grow. Lactobacilli have unusually low iron requirements compared with many competing organisms, so the direction of that shift is plausible but unquantified. Treated here as mechanism only.

Carvacrol and thymol disrupt bacterial membranes broadly and do not spare ingested lactic acid bacteria. Taking a concentrated essential oil at the same time as live cells can lower the viable count that arrives. Separating the doses is the usual practical response.

Berberine has direct antibacterial activity at intestinal concentrations and reshapes the gut community. Co-dosing with a live strain may reduce delivered viability, though no study here quantifies it for ME-3.