Bacteriën in de vagina: Zo moeder zo dochter?
De meeste kinderen komen ter wereld via het geboortekanaal van hun moeder, een omgeving die rijk is aan bacteriën. Maar vroeg jij je ooit al af of moeders vaginale bacteriën ook belangrijk zijn voor de latere gezondheid van haar kinderen? De afgelopen jaren werd er uitgebreid onderzoek verricht naar voordelige bacteriën in de vagina en hoe ze kunnen bijdragen aan het bevorderen van de gezondheid van vrouwen. Maar de exacte oorsprong van deze bacteriën – samen ook wel het vaginale microbioom genoemd - blijkt een groot mysterie. Wij onderzochten of het mogelijk is dat moeders vaginale bacteriën bij de geboorte worden doorgegeven en decennia later nog invloed hebben op de vaginale gezondheid van haar dochter. Bovendien weten we nog maar weinig over hoe de bacteriële gemeenschap in de vagina verandert tijdens de zwangerschap en hoe deze dynamiek een rol kan spelen bij zwangerschapscomplicaties zoals vroeggeboorte. Net omwille van deze mogelijke invloed op de volgende generaties is verder wetenschappelijk onderzoek cruciaal.
Vlaamse vagina’s, een goudmijn aan informatie
Het laboratorium voor Toegepaste Microbiologie en Biotechnologie aan de Universiteit Antwerpen startte in 2020 een grootschalig burgerwetenschapsproject onder leiding van professor Sarah Lebeer. Het voornaamste doel was onderzoeken hoe het met de vaginale gezondheid in Vlaanderen gesteld is. Het project kreeg de naam ‘Isala’ en resulteerde in een ruime collectie van meer dan 3000 zelf-afgenomen vaginale stalen, en daarbovenop een schat aan gedetailleerde informatie over de persoonlijke hygiëne, het voedingspatroon, het seksleven en andere levensstijlgewoontes van de deelneemsters. De verzameling aan intieme stalen en vragenlijstdata maakten reeds heel wat wetenschappelijk onderzoek mogelijk in het Isala labo. Zo weten we nu dat bij de meeste deelneemsters voornamelijk melkzuurbacteriën aanwezig zijn in de vagina. Dat is goed nieuws, aangezien deze bacteriën de vagina beschermen tegen infecties en ontstekingen. Ook nu, drie jaar later, steekt een enthousiast team van wetenschappers nog dagelijks de handen uit de mouwen om nog meer mysteries rond vaginale bacteriën te ontrafelen. Dankzij de omvang van de studiegroep kon er recent ook een selectie van deelnemende moeders en dochters gemaakt worden. Zij bieden nu heel wat nieuwe en waardevolle inzichten in de oorsprong van vaginale bacteriën.
Bacteriën ‘geërfd’?
Vaginale bacteriën behoren samen met bacteriën uit de darmen, op de huid, in de mond en in de moedermelk tot de eerste bacteriën waarmee een baby in contact komt. Dit eerste contact is van groot belang voor de verdere ontwikkeling en gezondheid van het kind. Onderzoek toonde reeds aan dat darmbacteriën van een moeder de samenstelling van het darmmicrobioom van haar kind op latere leeftijd beïnvloeden. De oorsprong van het vaginale microbioom blijft echter tot op heden grotendeels onbekend. Om te bepalen of het vaginale microbioom van een moeder hierbij bepalend is, onderzochten we vaginale stalen van Isala moeder-dochter paren. Daaruit bleek reeds dat bepaalde moeders en dochters zeer nauw verwante vaginale bacteriën delen, die mogelijks bij de geboorte zijn doorgegeven van moeder op dochter. Verder onderzoek wordt nu uitgevoerd om dit te kunnen bevestigen en andere routes uit te sluiten. Het zou immers ook kunnen dat het eten van dezelfde voedingsmiddelen, het gebruik van dezelfde badkamer of het gezamenlijk wassen van kleding hierbij een rol spelen. Een studie naar het vaginale microbioom van andere vrouwelijke huisgenoten kan hierbij zeker helpen. Denk hierbij maar aan lesbische partners, schoonzussen, adoptiedochters, enzovoort. Daarom besliste het Isala team om binnenkort een nieuwe oproep te lanceren.
Het belang van moeders vaginale bacteriën
Het is cruciaal om verder te onderzoeken welke factoren bijdragen aan de vorming van het vaginale microbioom. Deze nieuwe inzichten zijn van groot belang, niet alleen voor de vrouw in kwestie, maar ook voor haar eventuele partner en kind(eren). Een verstoorde bacteriële gemeenschap in de vagina kan namelijk niet enkel zorgen voor intieme ongemakken en infecties, maar kan ook bijdragen aan complicaties tijdens een zwangerschap. Vroeggeboorte komt naar schatting voor bij 7% van de zwangerschappen en behoort daarmee tot een van de meest voorkomende complicaties. Dit heeft ernstige gevolgen voor zowel kindersterfte, als de gezondheid van het kind op lange termijn. Op dit moment bestaan er enkele strategieën om het risico op vroeggeboorte te verminderen bij vrouwen met een hoog risico. Daarom is het essentieel om te zoeken naar indicatoren die wijzen op een zwangerschap met verhoogd risico. Om zulke indicatoren in het vaginale microbioom te vinden, moeten we eerst beter begrijpen hoe het verandert tijdens een zwangerschap. We hebben deze veranderingen onderzocht, op basis van vaginale stalen genomen tijdens elk trimester van de zwangerschap. Hieruit bleek dat de meeste vrouwen op de verschillende tijdstippen een stabiel microbioom hadden, dat voornamelijk bestond uit gezonde melkzuurbacteriën. Toch blijft er nood aan meer onderzoek bij zwangere vrouwen om veranderingen te herkennen die zouden kunnen wijzen op complicaties zoals vroeggeboorte. Hiervoor zijn er niet alleen meer stalen nodig van tijdens een zwangerschap, maar bij voorkeur ook van de periode ervoor en erna. In de komende jaren zullen wetenschappers in samenwerking met gynaecologen en hun patiëntes nog hard werken om deze dynamiek verder in kaart te brengen.
De toekomst
Hoewel er al veel werd ontdekt, blijven er nog heel wat mysteries rond het vaginale microbioom. De toekomst ziet er echter veelbelovend uit. Het monitoren van vaginale bacteriën tijdens een zwangerschap zou bijvoorbeeld niet enkel kunnen bijdragen aan het voorkomen van vroeggeboortes maar kan mogelijks ook verzekeren dat er goede bacteriën worden overgedragen naar de volgende generatie.
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