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Gut. Nov 1997; 41(5): 632–635.
PMCID: PMC1891556

Improved clinical tolerance to chronic lactose ingestion in subjects with lactose intolerance: a placebo effect?


Background—Uncontrolled studies of lactose intolerant subjects have shown that symptom severity decreases after chronic lactose consumption. Adaptation of the colonic flora might explain this improvement.
Aims—To compare the effects of regular administration of either lactose or sucrose on clinical tolerance and bacterial adaptation to lactose.
Methods—Forty six lactose intolerant subjects underwent two 50 g lactose challenges on days 1 and 15. Between these days they were given 34 g of lactose or sucrose per day, in a double blind protocol. Stool samples were obtained on days 0 and 14, to measure faecal β-galactosidase and pH. Symptoms, breath H2 excretion, faecal weight and electrolytes, and orofaecal transit time were assessed.
Results—Except for faecal weight, symptoms were significantly milder during the second challenge in both groups, and covariance analysis showed no statistical difference between them. In the lactose group, but not in the sucrose group, faecal β-galactosidase activity increased, pH dropped, and breath H2 excretion decreased.
Conclusion—Bacterial adaptation occurred when lactose intolerant subjects ingested lactose for 13 days, and all symptoms except diarrhoea regressed. Clinical improvement was also observed in the control group which displayed no signs of metabolic adaptation. This suggests that improved clinical tolerance may be just a placebo effect.

Keywords: lactose; lactose intolerance; colonic adaptation; lactase deficiency

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Suarez FL, Savaiano DA, Levitt MD. Review article: the treatment of lactose intolerance. Aliment Pharmacol Ther. 1995 Dec;9(6):589–597. [PubMed]
  • Johnson AO, Semenya JG, Buchowski MS, Enwonwu CO, Scrimshaw NS. Adaptation of lactose maldigesters to continued milk intakes. Am J Clin Nutr. 1993 Dec;58(6):879–881. [PubMed]
  • Florent C, Flourie B, Leblond A, Rautureau M, Bernier JJ, Rambaud JC. Influence of chronic lactulose ingestion on the colonic metabolism of lactulose in man (an in vivo study). J Clin Invest. 1985 Feb;75(2):608–613. [PMC free article] [PubMed]
  • Flourié B, Briet F, Florent C, Pellier P, Maurel M, Rambaud JC. Can diarrhea induced by lactulose be reduced by prolonged ingestion of lactulose? Am J Clin Nutr. 1993 Sep;58(3):369–375. [PubMed]
  • Vesa TH, Korpela RA, Sahi T. Tolerance to small amounts of lactose in lactose maldigesters. Am J Clin Nutr. 1996 Aug;64(2):197–201. [PubMed]
  • Suarez F, Levitt MD. Abdominal symptoms and lactose: the discrepancy between patients' claims and the results of blinded trials. Am J Clin Nutr. 1996 Aug;64(2):251–252. [PubMed]
  • Yuen CT, Price RG, Chattagoon L, Richardson AC, Praill PF. Colorimetric assays for N-acetyl-beta-D-glucosaminidase and beta-D-galactosidase in human urine using newly-developed omega-nitrostyryl substrates. Clin Chim Acta. 1982 Sep 15;124(2):195–204. [PubMed]
  • Marteau P, Pochart P, Flourié B, Pellier P, Santos L, Desjeux JF, Rambaud JC. Effect of chronic ingestion of a fermented dairy product containing Lactobacillus acidophilus and Bifidobacterium bifidum on metabolic activities of the colonic flora in humans. Am J Clin Nutr. 1990 Oct;52(4):685–688. [PubMed]
  • RADFORD EP, Jr, FERRIS BG, Jr, KRIETE BC. Clinical use of a nomogram to estimate proper ventilation during artificial respiration. N Engl J Med. 1954 Nov 25;251(22):877–884. [PubMed]
  • Hertzler SR, Savaiano DA. Colonic adaptation to daily lactose feeding in lactose maldigesters reduces lactose intolerance. Am J Clin Nutr. 1996 Aug;64(2):232–236. [PubMed]
  • Perman JA, Modler S, Olson AC. Role of pH in production of hydrogen from carbohydrates by colonic bacterial flora. Studies in vivo and in vitro. J Clin Invest. 1981 Mar;67(3):643–650. [PMC free article] [PubMed]
  • Eherer AJ, Fordtran JS. Fecal osmotic gap and pH in experimental diarrhea of various causes. Gastroenterology. 1992 Aug;103(2):545–551. [PubMed]
  • Vogelsang H, Ferenci P, Frotz S, Meryn S, Gangl A. Acidic colonic microclimate--possible reason for false negative hydrogen breath tests. Gut. 1988 Jan;29(1):21–26. [PMC free article] [PubMed]
  • Martini MC, Savaiano DA. Reduced intolerance symptoms from lactose consumed during a meal. Am J Clin Nutr. 1988 Jan;47(1):57–60. [PubMed]
  • Beaugerie L, Burger AJ, Cadranel JF, Lamy P, Gendre JP, Le Quintrec Y. Modulation of orocaecal transit time by hypnosis. Gut. 1991 Apr;32(4):393–394. [PMC free article] [PubMed]
  • Cann PA, Read NW, Cammack J, Childs H, Holden S, Kashman R, Longmore J, Nix S, Simms N, Swallow K, et al. Psychological stress and the passage of a standard meal through the stomach and small intestine in man. Gut. 1983 Mar;24(3):236–240. [PMC free article] [PubMed]
  • Marteau P, Flourie B, Pochart P, Chastang C, Desjeux JF, Rambaud JC. Effect of the microbial lactase (EC activity in yoghurt on the intestinal absorption of lactose: an in vivo study in lactase-deficient humans. Br J Nutr. 1990 Jul;64(1):71–79. [PubMed]

Figures and Tables

Figure 1
: Symptoms reported by the 46 lactose maldigesters during two identical 50 g lactose challenges, separated by a 13 day period during which they consumed 34 g of either lactose or sucrose daily. Results are expressed as means (SD).
Figure 2
: Individual results for faecal weight (g/12 h) of 24 lactose maldigesters during two identical 50 g lactose challenges, separated by a 13 day period during which they consumed 34 g of lactose daily.

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