Chronic SNS-HPA hyperarousal affects the gut microbiome and metabolic and immune settings

The gut is a major microbial-host interface, and a dominant immune organ.

Immune function, HPA axis regulation, and the microbiota-gut-brain axis interact and co-evolve in the mother-infant complex adaptive system, and are each affected by stress.

The infant gut microbiome in very early life has life-long effect on the settings of metabolism, immune, endocrine, and gut health. Gut dysbiosis is associated with impaired gut barrier integrity, inflammation and autoimmune disease.90, 91

The NDC neurobiological model proposes that widespread inappropriate medicalisation of infant behavioral cues, usually as signs of gut problems, results in a failure to identify and manage the underlying environmental factors which precipitate chronic SNS-HPA hyperarousal in very early life. Inappropriate medicalisation of upregulated behavior and the failure to identify and manage underlying clinical problems have deleterious effects on gut health long-term.

An infant who cries and fusses a lot in the first months of life is in a heightened pro-inflammatory state

Excessive infant crying, or chronic SNS-HPA hyperarousal, is a pro-inflammatory state, impacting on gut microbiome and permeability, with long-term effects on metabolic, immune and mental health in susceptible infants.94, 102 Chronic SNS-HPA hyperarousal releases cortisol, which alters intestinal motility, gut epithelial permeability, and induces changes in gut microbial composition.

The Affect Diathesis model theorises that behaviorally hypo-aroused infants also experience chronic SNS-HPA hyperarousal, with parasympathetic nervous system override, which would be expected to be similarly predispose a crying infant to pro-inflammatory states.21

Gut dysbiosis is not an idiopathic condition which results in infant pain and excessive crying

Instead of applying a linear and causative disease model which assumes that gut dysbiosis causes excessive infant crying, the neurobiological model of cry-fuss problems proposes that chronic SNS-HPA hyperarousal, proton pump inhibitors, and feeding problems interact in the complex adaptive system of the mother and infant, out of which gut dysbiosis emerges.31, 94-96

The neurobiological model of infant cry-fuss problems proposes that these and other environmental factors disrupt parent-infant biobehavioral synchrony, precipitating multiple trajectories of atypical development in a small subgroup of genetically or psychosocially susceptible infants.

Chronic inflammation is emerging as the critical pathophysiological feature of mental disorders generally, associated with dysregulation of normal microglial synaptic pruning.91

This does not mean, however, that gut dysbiosis or altered microbiome compositions cause infant pain, which causes infant crying. This popular hypothesis lacks an evidence-base, and is a linear or reductionist interpretation of existing evidence.

Gut health and the gestalt method of fit and hold in breastfeeding

Optimising gut health in susceptible infants requires not only avoidance of unnecessary medicalisation of unsettled infant behavior, but importantly, the support of breastfeeding success, with its known gut and immune protections.

A systematic review of ultrasound studies of breastfeeding mother-baby pairs forms the biomechanical basis for a new ‘gestalt’ model of clinical breastfeeding support, out of which the NDC gestalt breastfeeding approach is developed.112

Gestalt breastfeeding builds on the pioneering advance of baby-led breastfeeding, which emphasises cued care by activating and responding to the baby’s mammalian reflexes, but points to the evidence showing that this is not enough to achieve pain-free effective milk transfer for many women.94, 95

The gestalt approach educates about the biomechanics of effective breastfeeding. Impaired fit and hold and the resultant infant cues of fussing at the breast, difficulty coming onto the breast, back-arching, maternal nipple pain, marathon feeds, excessively frequent feeds, excessive night waking, and poor weight gain, are addressed applying gestalt methods.112, 113

Formula, which offers the human infant unphysiological doses of cow’s milk protein, lacks a myriad immune factors, micro-nutrients, and live bacteria, predisposing to short- and long-term gut dysbiosis and increased risk of immune system alterations. DNA methylation, a key mechanism of epigenomic regulation, is highly responsive to diet. Nutrients and bioactive compounds are known to alter the expression of genes at the transcriptional level and result in long-term phenotypic changes.4

However, women feed babies in complex contemporary sociocultural contexts, facing multiple disruptors, pain, and conflicting clinical advice. NDC is strictly non-judgemental concerning mode of infant feeding, and teaches paced bottle-feeding in order to optimise feeding-related reciprocity chains in formula or expressed-breastmilk-fed infants. NDC also identifies and manages conditioned dialling up with the bottle, which is commonly inappropriately medicalised. (Table 6)

The NDC approach of frequent flexible breastfeeds and gut health

The very frequent, irregular washing of the gut with small and large doses of the living tissue of the infant's mother's milk is, from an evolutionary perspective, fundamental to infant gut health and optimal trajectories of gut, immune and metabolic health throughout childhood and life-long.

References

The references for this article are found in the research publication found here.