Technical Aspects of Electrolyte Formulations

Further Technical Aspects of KRYPTADE and ENERVADE Formulations

Carbohydrate Form:
Food digestion of reducing substances (carbohydrates such as glucose requiring the enzyme lactase for digestion) occurs predominantly in the upper small intestine. The majority of solutes and passive water absorption occurs in the lower small intestine. Absorption of fluids is glucose and/or amino-acid dependant. When infant diarrhoea cereals (rice starch) are added to electrolytes there is a reduction of faecal volumes from 18 – 36% (non-cholera v cholera origin diarrhoeas). This additional absorption occurs in the colon based on fermentation of fermentable carbohydrates to n-butyrate. Large structural carbohydrates such as resistant maltodextrins and betacyclodextrin add carbohydrates (energy) without significantly altering the tonicity as would occur with high levels of smaller carbohydrate molecules such as glucose (dextrose). Given the rate of recovery from dehydration remains a primary goal formulations of ENERVADE and KRYPTADE avoid increases in tonicity so as to avoid reduction in the rate of gastric emptying.

Infections and Damage to Intestine:
Pathological changes associated with some infections may lead to different requirements in an electrolyte formulation. Rotavirus is especially affecting the upper small intestine and responsible for a mal-absorption diarrhea, whereas cryptosporidiosis affects the lower small intestine and is a secretory and mal-absorptive diarrhea. In infants, the ideal electrolyte formulations are not found to be equivalent when measuring outcomes for secretory (mainly cholera) compared with mal-absorptive (rotavirus and cryptosporidial) diarrhoeas (Raghupathy et al 2006).
This should serve as an indication that calf scours with a secretory component (i.e. some mixed infections – and especially those with cryptosporidiosis), may not respond equivalently to different electrolyte formulations compared to mal-absorptive causes of diarrhoea (rotavirus). Some research shows rotavirus also has been shown to produce a secretory stimulating enterotoxin (Ball et al 1996). There are greater effects on acid-base balances of an osmotic (mal-absorptive) diarrhea for the higher small intestinal infections with rotavirus, compared with lower small intestinal infections with cryptosporidiosis where dehydration from mal-absorption dominates the clinical signs. (Kukuruzovic et al 2002).

Energy:
Energy of electrolytes has been indicated in terms of kcal, and typically this is derived from the addition of dextrose (glucose). This simply defines one aspect of energy without regard to specific energy requirements of tissue type, and irrespective of tissues specifically affected by infectious agents. Frequently amino-acids, in particular glycinw or alanine are added as an alternative source for intestinal Na+ energy dependent activity; though even these alternative amino-acid pathways may be affected in cryptosporidiosis (Topouchian et al 2001).

Sodium Concentration:
Recent trial work suggests that there are major effects on the rate of influx v efflux of water, sodium, and glucose by changes in the mMol concentration of sodium(Subramanya et al 2006). This work (rat model normal intestine) suggests that minor ingredients can play a significant role in rates of passage of each component and that low sodium (60mMol/litre) is preferable to 90mMol/litre. Sodium concentration interacts to have major effects on this rate of influx v efflux of glucose, and water. Particular amino-acids, specifically arginine at very low concentrations can provide a significant enhancement in rates of influx over efflux and that this is also sensitive to sodium concentrations, with lower levels of sodium having higher ratios of influx/efflux (Wapnir et al, 1997).

KRYPTADE Features:
Kryptade has

  • arginine at low concentration,
  • moderately low concentration of sodium,
  • source of glucose and glycine to aid uptake of sodium but not as total body energy source,
  • source of fermentable carbohydrate as resistant maltodextrin – 10% digestible in small intestine and 50% fermentable in large intestine to provide a source of n butyrate for colonic fluid uptake.
  • maintains a low viscosity which could affect stomach emptying, and an isotonic solution to be gentle on the recovering gut lining.
  • Seaweed flavouring to enhance flavouring.

References
Ball, JM, Tian P, Zeng C Q-Y, Morris A P, & Estes M K. (1996) Age-dependent diarrhoea induced by a rotaviral nonstructural glycoprotein. Science, 101-103.
Kukuruzovic R, Robins-Browne RM, Anstey NM, Brewster DR (2002). Enteric pathogens, intestinal permeability and nitric oxide production in acute gastroenteritis. The Pediatric infectious disease journal, 21(8), 730-739.
Raghupathy P, Ramakrishna B, Oommen SP, Ahmed MS, Priyaa G, Dziura J, Young GP, Binder HJ (2006). Amylase-resistant starch as adjunct to oral rehydration therapy in children with diarrhea. Journal of pediatric gastroenterology and nutrition, 42(4), 362-368.
Subramanya S,Ramakrishna BS, Binder HJ, Farthing MJ, Young GP (2006) Evaluation of Oral rehydration Solution by Whole-Gut Perfusion in Rats: Effect of osmolarity, sodium concentration and Resistant Starch. Jl of pediatric Gastroenterology and Nutrition 43, 568-575
Topouchian A, Kapel N, Huneau JF, Barbot L, Magne D, Tome D, & Gobert JG. (2001). Impairment of amino-acid absorption in suckling rats infected with Cryptosporidium parvum. Parasitology research, 87(11), 891-896.
Wapnir RA, Wingertzahn MA, Teichberg S (1997). L-arginine in low concentration improves rat intestinal water and sodium absorption from oral rehydration solutions. Gut, 40(5), 602-607.

Other supplement targets

Other supplement targets

Colostrum and milk

Milk is considered the ideal nutritional source for the immature digestive system to meet a calf’s needs. Quite separate from its nutritional benefits, milk contains features which may aid the recovery of the damage of the intestine and the recovery of normal function. This includes some components which stimulates the mucus activity from goblet cells (metabolism and secretion) with mucus acting as a local barrier to pathogenic invasion. It may reduce the attachment of various pathogens E coli to the enterocytes. Or it may reduce rotavirus replication (Juntenen at al 2001).

The components in milk affecting goblet cells include growth factors (EGF, TGF-β, and KGF) found in milk (and colostrum), and parts of the casein fraction specifically β-casomorphin. (Plaisancie 2006). Milk may also act through its effect on bacterial populations and their effect on the innate and acquired immune system. EGF and its analogs are targeted for development as they have been shown to improve recovery by reducing inflammatory processes.

Anti-oxidants

There is a correlation between each of the following factors: (in animal models) (refer Doig et al, 1998)

Mucosal ischaemia (loss of blood flow)

Extent of the pathological injury to the mucosa

Severity of intestinal permeability

Severity of bacterial translocation

In order to advance treatment of the recovery of calves from intestinal infections including re-hydration with electrolytes, nutritional support including the use of targeted energy sources may improve treatment outcomes. These targeted sources may include supplements of anti-oxidants to reduce the increase in intestinal permeability (De Souza & Greene 2005). These anti-oxidants may act to limit cytokine activation, and reduce the central behavioural response to abdominal discomfort (see below) – leading to loss of appetite.

These may be further aided by

    1. Limiting further mucosal injury (by avoiding hypertonic fluids),
    2. Improving the rate of fluid re-hydration by minimizing fluid losses at the membrane (alanyl-glutamine).
      Alanyl-glutamine is a precursor of glutathione an important anti-oxidant for the intestinal and hepatic
      cells.
    3. Recognizing that the early severe insult from infections in spite of the above will in some calves lead
      to intestinal permeability changes, and
    4. Bacterial translocation will then become important. Recognizing the clinical signs of septicaemia
      becomes an important challenge separate from recognition of signs of de-hydration, hypothermia, and
      acidosis,
    5. Early re-hydration may be one of the most important ways to limit severe outcomes. (Early rehydration should be the fastest possible rehydration).

News

Thomson, Sarah (2016) Cryptosporidiosis in farm livestock. PhD thesis. Submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy, Institute of Biodiversity Animal Health and Comparative Medicine University of Glasgow 2016 http://theses.gla.ac.uk/7096/

This extensive and original research has highlighted some important features of Cryptosporidium parvum infections in calves based on the research completed in Scotland.

Some of the results may or may not have direct relevance to New Zealand farming conditions. In some instances they may be so relevant that they will challenge some of our current practices. Without some  local (NZ) studies it is too early to make recommendations.

Summary:

  1. Only one cow was shedding the genotypic strain variant that produced cryptosporidial scours for the calf shed. That cow calved early, and its calf developed cryptosporidial scours. These scours were apparently sufficient to spread the oocysts from that point on. While multiple genotypic strains occurred on the farm, it was only the one strain that emerged to be significant in the calf rearing environment.
  2. The PhD report included development of research study techniques that isolated Cryptosporidium parvum from cow dung, based on separation, concentration, identification and genotypic typing of the strains present. It confirms studies which suggest it is overwintering cows prior to calving potentially being the source of infection in a calf shed.
  3. No conclusions can be made of the shed being a source of infection between seasons. Within the season, the  shed and farmer practices  remains an important source for spread of infection between calves once the first calf has had cryptosporidial scours.
  4. The infective dose is an important element in determining the time of infection to the first signs on infection, with higher infective doses showing earlier and more severe signs.
  5. Strain (genotypic) variations exist which differ in severity of clinical signs. It is likely that strains producing more severe signs are contaminating the environment more successfully and ensuring their dominance as the ‘on-farm’ endemic type.

Comments: The actual output of crypto oocysts from a cow are below the detectable levels with current techniques routinely available without the research techniques of concentration that were used. Also the genotypic typing is a method that is not currently employed other than through the most advanced, specialised research laboratories.

 

Fibre

It is claimed that by the addition of fibre to a diet, there is a beneficial effect by maintaining intestinal barrier function and preventing bacterial translocation even in the absence of oral nutrients (Spaeth et al 1990). Some soluble dietary fibre even though fermentable remains only partially fermentable (Fibersol-2©), and has been reported to also produce beneficial intestinal morphological changes. All fibre is not equal however, with citrus pectin failing to providing benefits. However kaolin and cellulose fibre does provide benefit. The effect of fibre are seen with changes to intestinal morphology, mucosal mass, and gut bacterial ecology. Fibres having a high viscosity significantly slow stomach emptying. To maintain high rates of stomach emptying it is important that soluble dietary fibre does not affect the viscosity of the electrolyte solution. Fortunately there are complex carbohydrates that meet this objective. Soluble dietary fibres such as resistant maltodextrins (e.g. Fibersol-2©, and Nutriose© FB06 and FM06) do not adversely affect viscosity and maintain stomach emptying.

Response of Lactobacillus strains to Prebiotics (e.g. resistant maltodextrins)

Some information is available from studies comparing prebiotic’s  effects on Short Chain Fatty Acids (SCFAs), but not on the species of bacteria that are responsible for the changes (Flickinger et al 2000).

There is also data suggesting that some of the prebiotics included as resistant maltodextrins and betacyclodextrin have some limited effect on the degree of Lactobacillus fermentation in vitro (Hartemink 1999). However these reports are incomplete in several respects, and do not include L reuteri in the studies reported.

Studies show Non-Digestible Carbohydrates (NDOs) can show an increase of Lactobacilli numbers in spite of having no effect in in vitro studies. Typical of these is with resistant starch  (amylomaize) which leads to an elevation of lactobacilli that could not have been anticipated  since no lactobacilli utilized amylomaize starch in vitro.  This suggests that other bacteria fermenting the amylomaize are degraded to some extent by other bacteria which may supply some limiting factor to lactobacilli numbers.  (Conway et al 2001, q Brown et al 1998)

Conclusion: In vivo studies are required to show any prebiotic benefit. Contrary to this faecal numbers are not recommended to be reliable indicators of lactobacilli responses. Lactobacilli numbers may be prone to show the effects of stress, and reductions of numbers are reported to be lower in animals under stress (review Tannock 1983).

The role of the large intestine

Studies have shown that 60% of a standard electrolyte volume is excreted from failure of absorption (Naylor q. Guards & Tennant, 1986). The earlier separation of absorption between the small intestine and large intestine was shown to be false (Powell, q Nafatalin 1990) with fluid in a normal large intestine absorbed through the activity of butyrate driven sodium absorption ‘with colonic crypts being the final arbiter of stool fluidity’

It has been proposed that non-digestible carbohydrates are the origins of butyrate, being fermented by saccharolytic bacteria present in the large intestine. Not all complex carbohydrates deliver the same proportions of n-butyrate (see Ramakrishna el al 2000).

This includes

  1. resistant amylase starches (Ramakrishna et al 2000). The addition of resistant starch produced a significantly (p = 0.001) reduced period of diarrhoea compared with standard ORT for cholera. This was based on fermentable starch being reduced by 50% in transit through the large intestine, or the equivalent of 25g starch fermented per 2 litre dose of an isotonic electrolyte (327 mMol/L.).
  2. Resistant maltodextrins (e.g. Fibersol-2® – present in Enervade® and Kryptade®) See prebiotic carbohydrates below. Soluble dietary fibres differ in their effect on the recovery of damaged villus structure.
  3. It is also possible that undigested simple monosaccharides and disaccharides (lactose) overflowing undigested from the small intestine will also be fermented and potentially provide similar n-butyrate benefits.

The different carbohydrates (e.g. lactose versus starches) delivered to the large intestine ferment producing different ratios of SCFAs (short chain fatty acids), and therefore differ in n-butyrate production.

The colon is the site of significant sodium and water absorption normally which is dependant on energy from n-butyrate specifically. This is potentially an important target for enhanced fluid and electrolyte absorption in dehydrated calves.

Prebiotic carbohydrates

The large intestinal cells are dependant on Short Chain Fatty Acids (SCFAs) derived from the bacterial fermentation either from the overflow of undigested carbohydrates (e.g lactose) or non-digestible but fermentable more complex carbohydrates (prebiotic carbohydrates, pectins and rice etc). This enables the normal fluid absorption to also occur from the large intestine, and the generation of higher levels of vitamins (mainly B vitamins) from bacterial fermentation. The bacterial population of the large intestine associated with diarrhoea washout frequently is significantly lower with luminal bacteria significantly more severely affected than mucosal populations. Repopulating the ecological balance can be achieved with certain (stomach-acid resistant) probiotic strains, (Allen et al 2003). Probiotics act in concert with the immune system to provide a wide spectrum of activity. Prebiotics such as fructooligosaccharides act through the promotion of the natural gut flora’s beneficial bacteria (Oli et al 1998). The presence of carbohydrates with specific stereotypic bonding induces multiplication of different populations of saccharolytic bacteria in the large bowel, and this occurs in the recovering animal with diarrhoea (Oli et al 1998).

Probiotics and recovery from rotavirus & cryptosporidiosis

Allen et al 2003 has reviewed published papers on probiotics and human infant diarrhoeas. They examine aetiology and probiotic strains used. All results have been subject to review before being admitted for analysis. Their conclusion is that some probiotics do provide a useful adjunct to some diarrhoeas, with certain provisos also reported.

A report by Casas & Dobrogosz (2000) examines and report on one probiotic strain Lactobacillus reuteri . This strain is also included in the report by Timmerman et al.(2002) with benefits to calf general health following a mix of probiotic strains.

The conclusions from these reports is summarized

  • Strain specificity to the host species may be important to obtain clinical benefits.
  • Some strains are only suitable as live organisms and therefore subject to issues of storage.
  • Acid resistance of these strains to enable passage to the intestine is important. Some human strains marketed for their probiotic benefits fail to pass effectively in sufficient numbers to provide any benefit (UK data- Consumer)
  • Some strains of organisms researched and developed exhibit a range of effects that differ between strains. L reuteri for example has some antibacterial factors (reuterin).
  • Some may provide a dominant and exert an exclusivity which decreases the pro-inflammatory effects of other natural flora strains (Christiansen et al, 2002).
  • Health benefits occur outside the immediate gut environment (Timmerman et al, 2005).

Seaweed and fibres

Nutritional components included in some electrolytes include seaweeds. They are a source of natural dietary fibre. Alginates found in seaweed also stimulate mucus cells to release mucin. Other dietary fibres such as pectin, or gum Arabic do not have this direct effect (Plaisancie 2006). This benefit is therefore different from that achieved by bacterial fermentation and the production of butyrate for cellular energy. Seaweeds are also high in certain aminoacids which are also important constituents of mucin (e.g. threonine), and they also potentially aid palatability (pers. comm.)