Modification of sweet acidophilus milk to improve utilization by lactose-intolerant persons

Abstract

Enhanced digestion of yogurt by lactose-intolerant individuals is believed to be due to inherent beta-galactosidase (lactase) in the culture organisms that aids in the hydrolysis of ingested lactose. However, sweet acidophilus milk, which contains lactase-rich organisms, does not enhance lactose digestion. Using breath-hydrogen measurements to indicate malabsorption in 14 human subjects, we compared utilization of: milk, yogurt, heated yogurt, yogurt plus lactose, heated yogurt plus lactase, sweet acidophilus milk (SAM), and SAM made with sonicated cells. Results indicate that both the reduction of lactose during fermentation and the presence of indigenous bacterial lactase are responsible for the increased ability to tolerate lactose in yogurt. Improved utilization of SAM by sonication suggests that intracellular lactase is not available during digestion and that sonication releases the lactase activity from the cells.

Lactic acid bacteria and the human gastrointestinal tract

“…(Reprinted by permission of the author and Scandinavian University Press). (McDonough et al, 1987). The majority of studies (Table 3a) support that yogurt enhances absorption of lactose when compared with equivalent amounts of lactose in milk.…”

“…If, however, the bacterial cell-membranes are damaged by sonication, and intracellular lactase is released, breath hydrogen values were found in the same low level as for heated yogurt (McDonough et al, 1987). Thus, it seems that the bacterial lactase is not available or is insuf®cient to exert a measurable effect in sweet acidophilus milk during digestion, but can be made accessible after disruption of the cell membrane (Kolars et al, 1984;McDonough et al, 1987).…”

“…The rational for using fermented milk relates to the fact that lactose content is reduced between 25 and 50 percent during the fermented process (McDonough et al, 1987;Gorbach, 1990). Reduced malabsorption may, however, not only be associated with the decreased lactose concentration, but also to high lactase activities in yogurt (Kolars et al, 1984.…”

“…Since both products had little or no lactase activity, it was assumed that the difference was due to reduced lactose in the heated yogurt (McDonough et al, 1987). Similarly, when lactose was added to yogurt so that lactose concentration was equal to that in milk, the mean breath hydrogen value was signi®cantly lower than the value for milk, thus indicating a response to lactase activity (McDonough et al, 1987). This was further substantiated by adding commercial lactase to heated yogurt, in an amount that produced an activity level comparable to that found in yogurt, resulting in signi®cantly lower breath hydrogen test than for heated yogurt.…”

Hydrogen excretion upon ingestion of dairy products in lactose-intolerant male subjects: importance of the live flora

“…When yoghurt is heated before consumption, the concentration of living bacteria diminishes, depending on the conditions of heating. The consequences of this treatment are unclear: the production of hydrogen, which re¯ects the lactose maldigestion, is either enhanced after thermisation (Gilliland & Kim, 1984;Lerebours et al, 1989;McDonough et al, 1987) or unchanged (Martini et al, 1987;Shermak et al, 1995;Varela-Moreiras et al, 1992). This study was undertaken to determine whether the extent of the thermisation might explain those discrepancies and, more generally, to compare the responses to the ingestion of dairy products with different living¯ora contents in lactose malabsorbers.…”