A high molecular weight soluble fraction of tempeh protects against fluid losses in Escherichia coli-infected piglet small intestine

Enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhoea in children and piglets. Infection of ETEC results in fluid secretion and electrolyte losses in the small intestine. In this study the effects of tempeh, a traditional fungal fermented soyabean product, on fluid losses induced by ETEC infection in piglets was investigated. Pairs of ETEC-infected and non-infected small intestinal segments of piglets were perfused simultaneously for 8 h with pre-digested tempeh, its supernatant and saline as an internal control. In saline perfused segments, ETEC infection reduced net fluid absorption by more than 500 μl/cm2, whereas this reduction was significantly less for pre-digested tempeh and its supernatant (75 and 282 μl/cm2, respectively). The supernatant of pre-digested tempeh was also compared with its permeate and retentate fractions. These fractions were created by ultra-filtration and contained respectively low and high molecular weight (>5 kDa) compounds. Again ETEC infection caused a significant reduction of net fluid absorption when perfused with saline (386 μl/cm2) and also with the permeate fraction (300 μl/cm2), but much less with the supernatant and the retentate fraction (125 and 140 μl/cm2, respectively). The reduction in net fluid absorption upon ETEC infection when perfused with supernatant of either undigested or pre-digested tempeh was not different. Therefore from this study it can be concluded that a high molecular weight soluble fraction of tempeh is able to protect against fluid losses induced by ETEC, suggesting that this could play a potential role in controlling ETEC-induced diarrhoea.

Effect of osmolality on net fluid absorption in non-infected and ETEC-infected piglet small intestinal segments

In the small intestinal segment perfusion model the effect of osmolality on net fluid absorption in enterotoxigenic Escherichia coli (ETEC)-infected and non-infected small intestinal segments of piglets was investigated. In ETEC-infected segments net fluid absorption was reduced. Lowering the osmolality from 375 to 150 mOsmol/l by reducing sodium chloride concentrations increased net fluid absorption. There was a linear relationship between osmolality and net fluid absorption for both non-infected and ETEC-infected segments. Below 150 mOsmol/l the inverse relationship between osmolality and net fluid absorption disappeared. Substitution of sodium chloride with mannitol decreased net fluid absorption since mannitol cannot be actively absorbed. In ETEC-infected segments perfused with oral rehydration solution net fluid absorption significantly increased compared to a sodium chloride solution of similar osmolality, probably because of the high glucose concentration. Supplying hypotonic sodium chloride fluids to piglets can be beneficial in replenishing water and electrolyte losses in case of infectious diarrhoea.

In vivo and in vitro effects of tea extracts on enterotoxigenic Escherichia coli-induced intestinal fluid loss in animal models

OBJECTIVES

Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of dehydrating diarrhoea in infants and early-weaned piglets living under subhygienic conditions. We studied the effect of different tea types and subfractions on the intestinal fluid and electrolyte losses involved in ETEC diarrhoea.

MATERIALS AND METHODS

Jejunal segments of anaesthetised piglets were infected with ETEC or ETEC heat-labile toxin (LT) and subsequently perfused for 8 hours with control or tea solutions containing green or black tea extract (BTE) or 3 different BTE subfractions containing small-size, large-size or no phenolics. Changes in intestinal fluid and electrolyte net absorption were measured. To assess the antisecretory effects of tea, BTE was incubated before or after administration of the secretagogue forskolin in rat jejunal tissue placed in Ussing chambers and Cl- secretion measured as changes in short-circuit current (I(SC)).

RESULTS

Enterotoxigenic E. coli infection of piglet jejunal segments significantly reduced net absorption of fluid, Na+ and Cl- and increased net secretion of K+ compared with controls. Perfusion of the ETEC-infected segments with both 3 g/L green tea extract and BTE significantly inhibited these disturbances in fluid and electrolyte balance. The BTE subfraction rich in polymeric phenolics but not the other subfractions improved the fluid and electrolyte balance. Addition of forskolin to rat jejunal tissue induced a significant increase in I(SC). Pretreating but not posttreating the jejunal tissue with BTE inhibited the forskolin-induced increase in I(SC).

CONCLUSIONS

Tea may inhibit net fluid and electrolyte losses involved in secretory diarrhoea from ETEC.

Effect of processed and fermented soyabeans on net absorption in enterotoxigenic Escherichia coli-infected piglet small intestine

Infectious diarrhoea is a major problem in both children and piglets. Infection of enterotoxigenic Escherichia coli (ETEC) results in fluid secretion and electrolyte losses in the small intestine. In the present study the effect of processed and fermented soyabean products on net absorption during ETEC infection was investigated. Soyabean was processed into an autoclaved, a cooked and a mould-fermented (tempeh) product. The soyabean products were pre-digested and the effect of the products on net absorption in the small intestine of piglets was studied. Pairs of small-intestinal segments, one non-infected and the other ETEC-infected, were perfused simultaneously with the different products during 8 h. Net absorption of fluid, DM, Na, chloride, K and total solutes was determined. Net fluid absorption was highest for cooked soyabean followed by autoclaved soyabean and tempeh as a result of the osmolality of these products. In ETEC-infected segments, cooked soyabean and tempeh showed minor fluid losses (27 (SE 23) and 43 (SE 20) microl/cm(2), respectively) compared with the saline control (260 (SE 23) microl/cm(2)). Tempeh resulted in a high uptake of solutes. Processed soyabean products, particularly cooked soyabean and tempeh, are beneficial in maintaining fluid balance during ETEC infection. Additionally, tempeh showed high DM and total solute absorption. Therefore, particularly, tempeh may be beneficial in the case of post-weaning diarrhoea in piglets and possibly in children as well.

Effect of fermented soya beans on diarrhoea and feed efficiency in weaned piglets

AIMS

To evaluate anti-diarrhoeal and growth enhancing properties of fermented soya beans in weaned piglets.

METHODS AND RESULTS

In a first phase piglet diet, toasted full-fat soya beans (20%) were replaced with either cooked soya beans or Rhizopus microsporus or Bacillus subtilis fermented soya beans. The effect on the incidence, severity and duration of diarrhoea in enterotoxigenic Escherichia coli (ETEC)-challenged weaned piglets was determined (pen trial, 24 piglets per treatment). Severity of diarrhoea was significantly less on the diet with Rhizopus-fermented soya beans compared with the control diet containing toasted soya beans. Piglets fed fermented soya beans showed increased feed intake (13 and 12%), average daily weight gain (18 and 21%) and feed efficiency (3 and 8%) (for Rhizopus and Bacillus-fermented soya beans, respectively). However, in the treatment groups an unequal mortality and a potential unequal distribution of receptor-positive piglets were observed.

CONCLUSIONS

Cooked and fermented soya beans could be beneficial in the control of diarrhoea in ETEC-challenged weaned piglets (particularly Rhizopus fermented) and significantly improved weight gain and feed intake (particularly Bacillus fermented).

SIGNIFICANCE AND IMPACT OF THE STUDY

Fermented soya beans could offer benefits with respect to the control of diarrhoea and feed efficiency in piglets.

Inhibition of adhesion of enterotoxigenic Escherichia coli K88 by soya bean tempe

AIMS

Tempe is a traditional fungal fermented food made from soaked and cooked soya beans. It has been associated with antidiarrhoeal characteristics. This study investigated potential inhibitory effects of tempe on enterotoxigenic Escherichia coli (ETEC) K88.

METHODS AND RESULTS

Soya beans were soaked, cooked and subsequently fermented using several Rhizopus spp. Water-soluble filter-sterile extracts were tested for their ability to inhibit growth of E. coli and several indicator microorganisms and to inhibit adhesion of ETEC K88. Antimicrobial activity was found against Bacillus stearothermophilus only. ETEC K88-induced haemagglutination of hamster red blood cells was strongly inhibited by a number of tempe extracts and hardly by the cooked soya bean extract. Furthermore, several tempe extracts were able to inhibit adhesion of ETEC K88 to piglet small intestinal brush-border membranes.

CONCLUSIONS

Tempe appeared to interfere with ETEC K88 adhesion rather than showing growth inhibitory properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results indicate that tempe could exert an antagonistic effect against ETEC through inhibition of adhesion and might therefore have a protective effect against ETEC K88 infection in pigs. Hence, tempe could have potential to use as a feed supplement in the diet of weaned piglets.

In vitro digestibility of bacillus fermented soya bean

Bacillus fermented legume products include among others dawadawa and soumbala made from African locust bean, and natto and kinema made from soya bean. Bacillus subtilis is the dominant species involved in the fermentation. During Bacillus fermentation for 48 h of autoclaved soya bean the quantity of soluble and dialyzable matter increased from 22% and 6% up to 65% and 40%, respectively. Protein and carbohydrate degradation during fermentation of soya bean with several Bacillus spp. was investigated and appeared to be substantial during the first 18 h of fermentation resulting in the release of high levels of peptides and oligosaccharides. In vitro digestibility was increased from 29% up to 33-43% after Bacillus fermentation for 48 h. It was shown that Bacillus spp. were able to degrade soya bean macromolecules to a large extent resulting in water-soluble low molecular weight compounds. In vitro digestion of Bacillus fermented soya bean using gastrointestinal enzymes only slightly increased the amount of dialyzable matter, which clearly demonstrated the beneficial effect of Bacillus fermentation on food nutrient availability.

Solid-substrate fermentation of soybeans with Rhizopus spp.: Comparison of discontinuous rotation with stationary bed fermentation

Tempe is a soybean food obtained by stationary solid-substrate fermentation using moulds (mainly Rhizopus spp.) as starter organism. Traditionally, tempe is fermented in static layer trays or wrapped packages. Due to heat and mass transfer limitations, gradients of temperature and gas atmosphere will result. Agitated fermentation can help to level heat and mass gradients, yielding better homogeneity. This type of process will not result in traditional tempe, but in individually fermented soybeans that could be processed into food ingredients. This report deals with the comparative effect of stationary versus agitated solid-substrate fermentation of soybeans on some chemical indices of substrate modification. For agitated solid-substrate fermentation, a 450-l size rotary-drum bioreactor was designed and constructed. Of two Rhizopus spp. tested, R. microsporus tolerated agitation quite well, as judged by changes of pH, amino nitrogen, ammonia, and soluble dry matter. The other species, R. oligosporus was strongly affected by agitation. This resulted in less pH increase (difference approx. 1.5 units), lower amino nitrogen levels (30-50% of levels in static fermentation), and lower levels of water-soluble non-lipid dry matter (30-50% of levels in static fermentation) with R. oligosporus agitated fermentation of soybeans controlled at 30 and 37 degrees C, compared to static fermentation at temperatures ranging between 25-35 and 30-40 degrees C, respectively.

Myofibrillar ATPase activity in skinned human skeletal muscle fibres: fibre type and temperature dependence

1. Myofibrillar ATP consumption and isometric tension (P0) were determined in chemically skinned skeletal muscle fibres from human rectus abdominis and vastus lateralis muscle. Fibres were classified in four groups (I, IIA, IIB, IIA/B or mixed) based on myosin heavy chain composition. 2. ATP consumption (+/- S.E.M.) at 20 degrees C varied from 0.41 +/- 0.06 mmol l-1 s-1 in type IIB fibres (n = 5) to 0.10 +/- 0.01 mmol l-1 s-1 in type I fibres (n = 13). 3. The ratio between ATPase activity and P0 (tension cost) differed significantly between fast type II and slow type I fibres. At 12 degrees C tension cost was lower than the values found previously in corresponding fibre types in the rat. 4. The relative increase in ATPase activity for a 10 degrees C temperature change (Q10), determined in the range from 12 to 30 degrees C, was temperature independent and amounted to 2.60 +/- 0.06. The increase in P0 with temperature was smaller and declined when the temperature increased. 5. From these measurements, estimates were obtained for the maximum rate of isometric ATP consumption and force development at muscle temperature in vivo (35 degrees C).