SynoGut Ingredients
SynoGut lists ten ingredients: fibers, plant materials, a mineral clay and a probiotic. Individual amounts were not disclosed on the older label (see the Quality section).
Several, including oat bran, flaxseed and prune, are best studied as whole foods in gram-level servings, which a capsule is unlikely to match.
Psyllium Husk
Psyllium husk is the seed coat of Plantago ovata and the ingredient with the longest record in over-the-counter fiber products. To gauge scale, the FDA's authorized soluble-fiber and heart-disease claim (21 CFR 101.81) sets 7 grams a day of psyllium husk as its threshold. That rule concerns cholesterol and heart-disease risk, is not an assessment of SynoGut, and gives no basis to say the product qualifies for it, since its psyllium amount is undisclosed.
Bentonite Clay
Bentonite is a mineral clay that binds water and adsorbs other substances. Its industrial and cosmetic uses do not establish a digestive benefit when swallowed.
Purity is the practical concern: the FDA has warned consumers against one bentonite clay product after laboratory tests found elevated lead. Ask the seller about heavy-metal testing for the clay.
Black Walnut Hull
Black walnut hull is a botanical tied to traditional herbal preparations and sometimes recommended online for intestinal parasites. Tradition is not clinical evidence, and a suspected intestinal infection calls for medical assessment, not a supplement.
Oat Bran
Oat bran is the fiber-rich outer layer of the oat grain and a source of beta-glucan. The same FDA rule (21 CFR 101.81) sets 3 grams a day of oat beta-glucan for its heart-health claim. Whether the capsule comes anywhere near that is unknown, and nothing suggests it meets the claim.
Flaxseed
Flaxseed is a fiber-containing seed with a long history as a laxative. NCCIH notes that higher amounts may cause bloating, fullness and diarrhea.
Prune Fruit
Prune is simply dried plum. Whole dried plums have been studied for constipation, including in a randomized trial against psyllium, but a capsule of prune powder is a different form and amount, and the trial's details could not be checked.
Aloe Vera Leaf
With aloe vera leaf the preparation matters more than the name. NCCIH reports that oral aloe latex can cause abdominal pain, cramps and diarrhea, that non-decolorized whole-leaf extract is classed as a possible human carcinogen, and that inner-leaf gel is described as safe in short-term studies of up to 42 days.
The product details do not say which form is used.
Lactobacillus Acidophilus
Lactobacillus acidophilus is a common probiotic species. NCCIH says probiotic effects are strain-specific and that some products contain organisms other than those on the label.
A useful label names the strain and gives a CFU count guaranteed through expiration; neither appears in the product details, and that is the most important gap to close before buying.
Apple Pectin
Apple pectin is a soluble fiber that forms a gel with water and is common in foods and supplements. What it does depends on the type of pectin and the amount.
Glucomannan Root
Glucomannan is a soluble fiber from konjac root. The NIH Office of Dietary Supplements summarizes trials of gram-level amounts that found no consistent effect on body weight, so its presence should not be read as a weight-loss feature.