Antibacterial properties – Iron-rich smectite and illite clay (Montmorillonite/ bentonite type of clay) is effective in killing bacteria in vitro. Authors report that the clay mineral,
“…exhibits bactericidal activity against E. coli, ESBL [Extended-Spectrum Beta-Lactamases] E. coli, S. enterica serovar Typhimurium, P. aeruginosa, and M. marinum, and significantly reduces growth of S. aureus, PRSA, MRSA, and nonpathogenic M. smegmatis approximately 1,000-fold compared to cultures grown without added mineral products.”
Another study of more than 20 different clay samples from around the world, including the bentonite-type clays achieved promising results against MRSA superbug infections and disease.
Trace minerals – Clays contain massive amounts of trace minerals, necessary for good health. (For example, it is common to see as many as 75 different trace minerals in Montmorillonite clays.) This may explain many of the healing properties of clay. Specific trace minerals that various clays possess vary very widely. Also, the amount of any particular trace mineral in any specific clay varies a lot among clays from different locations. For example, the amount of iron in various bentonite clays can vary from well below 1%, and up to 10%.
Mud baths – Mud baths are perhaps the most common use of clay. Almost all health spas around the world use clay on a daily basis, and report health benefits for bathers.
Skin infections – Many types of skin infections have been healed by the application of medicinal clay (this was already noted in ancient times by Galen). For example, montmorillonite has shown its effectiveness in this area. It has also shown itself useful for tissue engineering.
As Carretaro et al. say, “Clays can eliminate excess grease and toxins from skin, and hence are very effective against dermatological diseases such as boils, acne, ulcers, abscess, and seborrhoea.”
Clay is used in many dermatological over-the-counter remedies, such as in acne treatments (this information may not be mentioned on the label specifically).
Use in bandages – In April 2008, the Naval Medical Research Center announced the successful use of a Kaolinite-derived alumino-silicate nanoparticles infusion in traditional gauze known commercially as “QuikClot Combat Gauze”.
According to one theory, “In the stomach, the negative electrical charges of tiny clay particles attract positively charged toxins from stomach fluids. This clumping prevents very small particles, such as toxic molecules, from passing through the walls of the intestines and entering the bloodstream.”
There are many over the counter remedies for internal use that contain clay. A popular example is tablets such as Kaopectate (Upjohn).
Numerous medicines also use Kaolinite clay, which has long been a traditional remedy to soothe an upset stomach. Also, Kaolin is or has been used as the active substance in liquid anti-diarrhea medicines such as Kaomagma.
Candida – Clays have proven to be effective against the Candida albicans infections. This is a type of a fungus (or yeast), which is a causal agent of opportunistic oral and genital infections. This type of infection, known as Candidiasis, also may enter the bloodstream, and become a systemic Candida infection.
In 1971, the influence of bentonite clay on the growth of Candida lipolytica has been studied by Maignan and Pareilleux. A clearly unfavorable effect of bentonite on Candida lipolytica growth in vitro was observed 
According to a 2009 study by Ghiaci et al. published in Applied Clay Science, bentonite clay acts very strongly against Candida: “The modified bentonite with monolayer surfactant (BMS), was the best support, for immobilization.”
Heavy metal chelation – Chelation therapy is the use of chelating agents to detoxify poisonous metal agents such as mercury, arsenic, and lead by converting them to a chemically inert form that can be excreted without further interaction with the body, to treat cases of severe heavy metal poisoning. It is also used as a dangerous, scientifically unsupported treatment for heart disease and autism.
Clay has proven to be a very effective chelating agent. Oyanedel-Craver and Smith have studied sorption of four heavy metals (Pb, Cd, Zn and Hg) to 3 kinds of bentonite clay. The overall conclusion of the study was that the organo-clays studied have considerable capacity for heavy metal sorption.
Irritable bowel syndrome – “[B]eidellitic montmorillonite is efficient for C-IBS patients (suffering from constipation-predominant irritable bowel syndrome)…”
Use by the NASA Space Program – The effects of weightlessness on human body were studied by NASA back in the 1960s. Experiments demonstrated that weightlessness leads to rapid bone depletion, so various remedies were sought to counter that. A number of pharmaceutical companies were asked to develop calcium supplements, but apparently none of them were as effective as clay. Dr. Benjamin Ershoff of the California Polytechnic Institute demonstrated that the consumption of clay counters the effects of weightlessness. He reported that “the calcium in clay …is absorbed more efficiently … [clay] contains some factor or factors other than calcium which promotes improved calcium utilization and/or bone formation.” He added, “Little or no benefit was noted when calcium alone was added to the diet.”
Health-e-Solutions Comment: The best type of clay to draw out unwanted toxins and achieve the most health benefit is calcium-bentonite clay. It has a pH of about 9.5 (very alkaline!), and has been proven time and time again to have the best absorptive properties. We used Montmorillonite clay as a supplement with our boys during the first year or so of their diabetic-alkaline lifestyle.
17. ^ Haydel, S.; Remenih, C.; Williams, L. (2008). “Broad-spectrum in vitro antibacterial activities of clay minerals against antibiotic-susceptible and antibiotic-resistant bacterial pathogens.”. The Journal of antimicrobial chemotherapy 61 (2): 353–361. doi:10.1093/jac/dkm468. PMC 2413170. PMID 18070832. edit
18.^ Haydel, S.; Remenih, C.; Williams, L. (2008). “Broad-spectrum in vitro antibacterial activities of clay minerals against antibiotic-susceptible and antibiotic-resistant bacterial pathogens.”. The Journal of antimicrobial chemotherapy 61 (2): 353–361. doi:10.1093/jac/dkm468. PMC 2413170. PMID 18070832. edit (full text of the article)
19. ^ Apr 7, 2008. “Healing clays” hold promise in fight against MRSA superbug infections and disease. (accessed 31 March 2009
20. ^ Falkinham Jo, 3.; Wall, T.; Tanner, J.; Tawaha, K.; Alali, F.; Li, C.; Oberlies, N. (2009). “Proliferation of antibiotic-producing bacteria and concomitant antibiotic production as the basis for the antibiotic activity of Jordan’s red soils.”. Applied and environmental microbiology 75 (9): 2735–2741. doi:10.1128/AEM.00104-09. PMC 2681674. PMID 19286796. edit
22. ^ A systematic review of contact dermatitis treatment and prevention. Saary J, Qureshi R, Palda V, DeKoven J, Pratt M, Skotnicki-Grant S, Holness L. J Am Acad Dermatol. 2005 Nov;53(5):845. Review.
24. ^ Cytotoxic assessment of L-ascorbic acid/montmorillonite upon human dermal fibroblasts in vitro: MTT activity assay. Lee, Y.-H., Chen, B.-Y., Lin, F.-H., Lin, K.-Y., Lin, K.-F. 2008 Biomedical Engineering – Applications, Basis and Communications 20 (6), pp. 337-343
25. ^ Preparation of biomimetic three-dimensional gelatin/montmorillonite-chitosan scaffold for tissue engineering. Zheng, J.P., Wang, C.Z., Wang, X.X., Wang, H.Y., Zhuang, H., Yao, K.D. 2007 Reactive and Functional Polymers 67 (9), pp. 780-788
26. ^ Carretaro MI, Gomes CSF, Tateo F. “Clays and human health.” In: Bergaya F, Theng BKG, Lagaly G, editors. Handbook of Clay Science, Developments in Clay Science. Vol. 1. Elsevier Ltd; Amsterdam: 2006. pp. 717–741. ISBN 0-08-044183-1 p. 722
30. ^ Maignan C and Pareilleux A, Influence of bentonite on the growth of Candida lipolytica. Comptes rendus hebdomadaires des seances de l’Academie des sciences. Serie D: Sciences naturelles 273(9):835-8, 1971 Aug 30
31. ^ Pareilleux A, Maignan C., Can J Microbiol. 1976 Aug;22(8):1065-71. [Metabolic activity of Candida lipolytica adsorbed to bentonite with hydrophobic chains] [Article in French]abstract and a link to full text
32. ^ M. Ghiaci, H. Aghaei, S. Soleimanian, M.E. Sedaghat S, “Enzyme immobilization: Part 1. Modified bentonite as a new and efficient support for immobilization of Candida rugosa lipase.” Applied Clay Science, Volume 43, Issues 3-4, March 2009, Pages 289-295
33. ^ Hazards of chelation therapy:
- Brown MJ, Willis T, Omalu B, Leiker R (2006). “Deaths resulting from hypocalcemia after administration of edetate disodium: 2003–2005”. Pediatrics 118 (2): e534–6. doi:10.1542/peds.2006-0858. PMID 16882789.
- Baxter AJ, Krenzelok EP (2008). “Pediatric fatality secondary to EDTA chelation”. Clin Toxicol (Phila) 46 (10): 1083–4.doi:10.1080/15563650701261488. PMID 18949650.
35. ^ Immunization Safety Review Committee, Board on Health Promotion and Disease Prevention, Institute of Medicine (2004).Immunization Safety Review: Vaccines and Autism. Washington, DC: The National Academies Press. ISBN 0-309-53275-2.
36. ^ Oyanedel-Craver VA, Smith JA, “Effect of quaternary ammonium cation loading and pH on heavy metal sorption to Ca bentonite and two organobentonites”. J Hazard Mater 2006; 137:1102-14.
37. ^ Ducrotte P, Dapoigny M, Bonaz B, Siproudhis L. “Symptomatic efficacy of beidellitic montmorillonite in irritable bowel syndrome: a randomized, controlled trial”. Aliment Pharmacol Ther. 2005 Feb 15;21(4):435-44. available online
38. ^ M A Abdel-Wahhab, S A Nada, I M Farag, N F Abbas, H A Amra, “Potential protective effect of HSCAS and bentonite against dietary aflatoxicosis in rat: with special reference to chromosomal aberrations.” Nat Toxins – 1998 (Vol. 6, Issue 5, Pages 211-8)
39. ^ I. K. IBRAHIM, A. M. SHAREEF, K. M. T. AL-JOUBORY, “Ameliorative effects of sodium bentonite on phagocytosis and Newcastle disease antibody formation in broiler chickens during aflatoxicosis”. Research in Veterinary Science, Volume 69, Issue 2, October 2000, Pages 119-122