Maternal breast milk is the usual food source for infants, though when breastfeeding is not possible, artificial lactation can be provided in the form of starting formulas, with the introduction of follow-up formulas 4-6 mo later, to ensure optimum nutritional development. During this period mild gastrointestinal disorders (MGDs) are not uncommon, and may be treated with dietetic measures.
This study for the first time provides information on the prevalence of these disorders in Spain, and on the efficacy of dietetic treatment using the different formulas of the Novalac product range. The results of the prevalence study indicate that colic in infants is the MGD most often seen in paediatric clinics (9.2%), representing 33.3% of all MGDs.
Infant “colic” is an ill-defined term that is often used in reference to different situations found in paediatric practice[16
]. Due to the lack of a clear definition, prevalence and treatment studies characteristically include heterogeneous groups of infants. These are usually healthy children that in the first four months of life develop paroxysmal crying without any apparent cause, and that gradually subsides. The underlying aetiology has not been clearly established, though the disorder has been related to alterations in motility[8
], prostaglandin dysfunction, abnormal serotonin concentrations, and neuropeptide immaturity. Other authors more inclined to seek behavioural explanations tend to relate infant colic to alterations in the family environment, or even consider it a “normal” form of behaviour in infants with a more irritable temperament.
Human milk contains 7 g of lactose per 100 mL. However, in the first few weeks of life, infants present physiological or functional lactase insufficiency that limits absorption of these amounts. The non-hydrolyzed lactose reaches the colon, where it ferments to yield lactic acid, short-chain fatty acids, methane, carbon dioxide and hydrogen. This exerts a beneficial effect in that the stools become semiliquid as a result. However, is some cases such fermentation gives rise to excess gas[17–19
], which favours the development of colic. In effect, different studies have related excess crying with excess intestinal gas[20
The Novalac Anti-Colic formula offers an important reduction of the symptoms. Colic was resolved in 87% of the cases within one week, with a reduction in crying time, improvement in feeding continuity, and a reduction in the amount of intestinal gas.
In this study, constipation was the cause of consultation in 7.8% of the infants (representing 28% of all MGDs). A recent article published by Quinlan et al[21
] studied the stool characteristics of 844 infants between 7-15 d old. Hard stools were recorded in 17% of the formula-fed infants, and in none of the breastfed infants. Breastfeeding entails a series of compensating physiological mechanisms that avoid constipation[22
]. The Novalac Anti-Constipation formula bases its therapeutic efficacy partially on its high lactose content (8.1 mg/100 mL). The non-hydrolyzed lactose reaches the colon, where it is metabolized by the anaerobic flora, producing an osmotic laxative effect, since it attracts water into the intestinal lumen[17–19
]. The magnesium contained in the formula (within the authorized maximum limits: 9.1 mg/100 mL) also enhances the laxative effect due to its osmotic action, and stimulates bowel motility by inducing cholecystokinin (CCK) secretion[23–25
]. The efficacy of such treatment is reflected by an increase in the number of stools, and a reduction in the number of hard depositions, associated discomfort and the need for external help in defecation.
The next most prevalent MGD in the present study was regurgitation (22% of the total MGDs). Regurgitation and vomiting are the final manifestation of reflux. The aetiology of reflux in infants is of a multifactorial nature, and has not yet been fully elucidated. Postprandial reflux is accepted to be physiological, and occasionally occurs in almost all infants. However, in some cases the clinical picture is particularly manifest and can produce important discomfort for both the child and family. It is generally agreed that uncomplicated gastro-oesophageal reflux should not receive pharmacological treatment (antacids, prokinetic agents, H2 receptor blockers), though effective measures such as postural and dietetic management are recommended. In any case, the same authors that initially recommended such treatment have recently questioned it[26
Milk thickening is a therapeutic practice that has been recommended for decades. Increased food viscosity and density reduces the reflux rate but does not modify the rest of parameters indicative of pathological gastro-oesophageal reflux. The products used as thickeners for the most part have been locust bean flour, pectin and cellulose. Cereal starch (rice and corn) has also been proposed, and offers the advantage of avoiding the possible adverse effects associated with the presence of galactomannans[27
]. The Novalac Anti-Regurgitation formula contains a specially selected corn starch (having high amylopectin content) in a proportion of 1.9 g per 100 mL. It is pregelatinised and contributes to the increased viscosity in the stomach (on average 10 fold the viscosity in the feeding bottle). The presence of medium-chain fatty acids in turn favours a reduction in gastric emptying[28
]. The efficacy of the treatment is reflected by the results obtained in the present study. In effect, the number of regurgitations/vomiting episodes decreased during the 7 d of treatment, and improvements were also seen in the rapidity of bottle ingestion, with a larger ingested volume.
Lastly, acute gastroenteritis represented 16.5% of the global MGDs in our study. Acute gastroenteritis, of a bacterial or viral origin, is characterized by alterations in the normal displacement of water and electrolytes within the intestinal lumen. When diarrhoea is caused by a virus (fundamentally rotavirus) transient lactase deficiency may also result. The duration of this deficiency is usually 7-15 d, though infants that are malnourished or suffer serious intestinal lesions may have persistent diarrhoea for up to 18-24 mo. In those cases in which deficient lactose absorption is suspected, lactose-free formulas are justified[29,30
]. In most cases a single week of lactose exclusion suffices, after which the usual formula is reintroduced, while monitoring tolerance.
The most recent developments point to the advisability of introducing soluble fibre[31
]. The use of amylase-resistant carbohydrates is an innovation that takes advantage of the functional properties of the colon - specifically, the metabolic activity of the anaerobic flora and the absorption capacity of the colon mucosa. The purported mechanism involves use by the colon mucosa of the short-chain fatty acids produced by bacterial metabolism of non-absorbed carbohydrates, to favour the absorption of water and electrolytes[32
]. In the colon, many carbohydrates are fermented by the anaerobic flora, resulting in short-chain fatty acids: propionate, acetate and butyrate. In the mucosa, these fatty acids stimulate the absorption of water and electrolytes.
The Novalac Anti-Diarrhoea formula contains no lactose, and moreover incorporates a series of novelties. The presence of electrolytes within the accepted maximum range (31 mg of Na/100 mL, 83 mg of K/100 mL and 49 mg of Cl/100 mL) ensures an increased mineral supply for those patients who after discontinuing oral rehydration remain at risk of excessive losses. On the other hand, the presence of pectin (1.5 g per 100 mL) offers the advantage versus other fructo-oligosaccharides of being totally fermented in the colon, since it is a larger and more viscous molecule - thereby favouring short-chain fatty acid production.
The present study for the first time offers information on the prevalence of mild gastrointestinal disorders in Spanish infants under four months of age seen in paediatric clinical practice. Dietetic intervention with the Novalac formulas has been shown to be effective in resolving these disorders in the routine clinical setting - with a significant reduction in associated symptoms. A close relationship has been found between satisfaction among the parents/tutors and paediatricians and the effectiveness of the dietetic treatment provided. In turn, the low prevalence of treatment-related adverse events reflects the good tolerability of the formulas belonging to the Novalac range of products.