Natural Foods Merchandiser

New Lactobacillus Strains Need Research

Doctor's Insight

Ten years ago, many gastroenterologists quietly snickered when the patients I referred to them announced they were taking probiotics. Today, these same physicians often recommend lactobacillus to their own patients. I believe many doctors have forgotten that just a decade ago they considered this treatment to be alternative medicine.

What changed? It's not just the increased interest in natural products because treating Helicobacter pylori infections with garlic and healing irritable bowel syndrome and candida with marshmallow root are still well outside mainstream medicine.

However, something unique has happened with lactobacillus. Combined money and interest is making it possible for lactobacillus to be researched in double-blind, controlled studies—the kind that even skeptics read and respect.

It is both heartening and sad (and possibly even threatening to the natural products industry) that of lactobacillus strains being sold, the majority of first-rate research has been conducted on just one brand, Culturelle, a product containing the patented Lactobacillus GG strain.

Launched by researchers at Tufts University in Boston, Culturelle does not currently market through natural products stores, but only through pharmacies, physicians, and directly to the public on the Internet. My gastroenterology colleagues perceive the name Culturelle as synonymous with lactobacillus and the only brand they trust. Although ConAgra's Culturelle is not the only lactobacillus strain shown to be effective, no other companies have matched ConAgra's research investment.

Lactobacillus rhamnosus HN 001
Notably, the Lactobacillus rhamnosus HN 001 strain is also able to enhance the immune system. Study results show that L. rhamnosus increases the ability of white blood cells to more effectively swallow and kill bad bacteria. Also, L. rhamnosus dramatically increases the tumor-killing effects of the lymphocytes' natural killer (NK) cells.

Researchers from the National University of Taiwan and Massey University in New Zealand collaborated on the first human study of L. rhamnosus to determine if this newly isolated strain had the same potent immune-stimulating effects as it had in previous studies on laboratory animals.1

Researchers enrolled volunteers who were healthy, middle-aged and older (mean age 63) and who were not lactose intolerant. For the study's first three-week run-in phase, all subjects consumed plain milk twice a day. During the second three-week treatment-vs.-placebo phase, subjects drank either L. rhamnosus-enriched or plain milk (placebo). Finally, everyone drank plain milk for the third three-week, wash-out period.

The results showed no significant immune system changes during the run-in period, when everyone was on placebo. However, in the treatment-vs.-placebo phase (weeks four to six), the white blood cells of subjects taking L. rhamnosus more effectively killed bacteria. Before taking lactobacillus, approximately 74 percent of the subjects' NK cells were able to engulf and kill bacteria. This increased to about 88 percent after three weeks on lactobacillus, representing a 19 percent increased ability to kill bacteria.

Because NK cells are among the body's main defenses against cancer, lactobacillus effects can be truly dramatic. The plain-milk diet did not induce the NK cells to kill cancer cells specifically, while in the lactobacillus treatment groups, the NK cell's ability to fight cancer more than doubled.

Current research indicates that many, but not all, lactobacillus strains can enhance immune function. But most lactobacillus strains have not been clinically tested in double-blind, clinical studies, with the exception of Culturelle's L. GG.

Of course, the true test of a product is not what it does to cells in a test tube but how it contributes to preventing or treating disease in people. The research is encouraging. The National Library of Medicine's medical research database includes the following double-blind studies. Six studies show lactobacillus' ability to treat or prevent diarrhea in children. Five of these studies used Culturelle.2 Four studies showed lactobacillus reduces allergic reactions from food. All four used Culturelle.3,4 One intriguing study showed lactobacillus reduces bladder cancer recurrence rate.5

Three studies showed lactobacillus can improve the treatment of the Helicobacter pylori bacteria, a common cause of ulcers and gastritis. One of these studies used Culturelle.6 Another study showed Lactobacillus plantarum (DSM 9843) may be an effective treatment for irritable bowel syndrome, reducing abdominal pain and gas.7

An even more impressive study showed dramatic improvement in preventing ulcerative colitis flare-ups.8 Researchers combined four strains of lactobacilli: three strains of bifidobacteria and one strain of the bacterium Streptococcus salivarius.

These research advancements create an opportunity to expand our knowledge and research base. But research using just one product poses a threat for those who cannot or will not compete at this level.

Richard N. Podell, M.D., M.P.H., is director of the Podell Medical Center in New Providence, N.J.


1. Sheih V. Systemic immunity-enhancing effects in healthy subjects following dietary consumption of the lactic acid bacterium Lactobacillus rhamnosus HN 2001. J Am Coll Cl Nutr 2001;20:149-56.

2. Vanerhoof J. Lactobacillus GG in the prevention of antibiotic-associated diarrhea in children. J Pediatr 1999;135:535-7.

3. Pelto L. Probiotic bacteria down-regulate the milk-induced inflammatory response in milk-hypersensitive subjects but have an immunostimulatory effect on healthy subjects. Clin Exp Allergy 1998;28:1474-9.

4. Kalliomaki M. Probiotics in primary prevention of atopic disease: a randomized placebo-controlled trial. Lancet 2001;357:1076-9.

5. Aso Y. Preventive effect of a Lactobacillus casei preparation on the recurrence of superficial bladder cancer in a double-blind trial. Eur J Urol 1995;27:104-9.

6. Feller C. Favourable effect of an acidified milk (LC-1) on Helicobacter pylori gastritis in man. Eur J Gastroenterol Hepatol 2001;13:25-9.

7. Noback, S. Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome. Am J Gastroenterol 2000;95:1231-8.

8. Gionchetti P. Oral bacteriotherapy as maintenance treatment in patients with chronic pouchitis: a double-blind, placebo-controlled trial. Gastroenterology 2000;119:584-7.

Natural Foods Merchandiser volume XXIII/number 9/p. 44-45

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.