If you’re heading for menopause, the word “estrobolome” could soon become familiar. It’s the term for a group of gut microbes that interact with female hormones – and they’re an argument for eating more fibre.
This gut-hormone relationship is a two-way street, says Sydney-based dietitian Nicole Dynan. On one hand, gut microbes influence how women’s bodies process oestrogen; on the other, oestrogen influences gut microbes.
“As oestrogen levels fall around menopause, there’s often less diversity in women’s gut microbes. But we also know that some gut bacteria and their enzymes – the estrobolome – have a role in recycling oestrogen. Once oestrogen has been picked up by the liver for removal, these bacteria can reactivate it so that some oestrogen can be reabsorbed, rather than excreted.
“Theoretically, this could help preserve more circulating oestrogen and possibly improve perimenopause symptoms – but it’s an emerging area of research and there are no studies that prove it,” she says.
Still, there are clues that a diverse gut microbiome can help, Dynan adds.
One is that some studies report that women with more microbial diversity have higher circulating oestrogen levels after menopause than those with lower diversity.
There’s also some evidence that whole soy foods like tofu, tempeh and edamame have benefits at perimenopause. These may be greater in women with a group of gut microbes that turn soy compounds called isoflavones into equol, a molecule that acts like a weak oestrogen, Dynan says.
But not all women have these bacteria.
Why Japanese women have fewer hot flushes
“Around 30 per cent to 50 per cent of people have the bacteria needed to make equol,” Dynan says. “Rates tend to be higher in Asians and lower in Westerners – and may explain why some studies find that Japanese women have fewer and less severe hot flushes than Western women. It’s thought to be linked to eating more foods like tofu and edamame, and having more equol-producing bacteria.
“But soy foods are still worth including, whether or not you produce equol. They’re a good source of plant protein and fibre, they’re linked with better heart and bone health, and their plant compounds seem to offer something even for women who don’t produce equol.
“We still can’t say that changing your diet directly changes hormone levels but a diverse microbiome seems to support many aspects of health, including gut health, says Dynan.
She points to a survey of menopausal and perimenopausal women presented to The Menopause Society last year that found that 94 per cent reported digestive problems. Most said their symptoms started or worsened at perimenopause or menopause. Bloating was the most common, followed by constipation, pain and reflux.
Bloating is also the most common digestive complaint Dynan hears from women at this life stage.
“Low fibre intake is likely to contribute to this. In my experience, many women start restricting foods to manage weight around the middle. This can mean eating less fibre just when they’re most likely to need it,” she says. “Instead of restriction, I focus on gradually increasing fibre, plant diversity and diet quality.”
Why our microbiomes are starved of fibre
Our gut microbiomes need more fibre, adds Dr Hayley O’Neill from Bond University’s Faculty of Health Sciences and Medicine.
“Starving your microbiome of fibre is linked to reduced diversity – yet although women need 25g of fibre daily, we know that 80 per cent of Australians don’t get enough. Ultra-processed foods now make up more than 40 per cent of the Australian diet. These foods are often high in refined carbohydrates, with little fibre.
“It’s possible that more fibre will reduce perimenopause symptoms but there are still no studies proving it,” says O’Neill, whose recent review of research into how lifestyle habits affect the female microbiome found a dismal lack of research.
However, there’s evidence that lifestyle factors beyond diet can impact the microbiome.
“Obesity, alcohol and smoking all cause inflammation which can reduce microbial diversity, too,” says Isabella Davidson, also from Bond University, who led the review.
Ideally, women should prep for perimenopause before it kicks in, says O’Neill.
“Prepare for it like you would for a marathon and start in your 30s, rather than flick into damage control when you get symptoms. A healthy lifestyle with a good diet and maintaining a healthy weight gives you a better chance of an easier time.”
Gently does it: How to introduce more fibre
“I usually start people with gentler fibres first – things like chia, ground flaxseed, oats, kiwifruit or psyllium, “says Dynan. “I suggest choosing one food, and introducing a small amount, with plenty of water, then giving the gut a week or so to adjust before adding anything else like more vegetables, fruit, whole grains, nuts and seeds.
“I leave the most fermentable fibres until last and introduce them gradually. They’re in foods like legumes, onion, broccoli and cauliflower – great for the gut but those most likely to cause wind if introduced too quickly. ”
Symptoms like bloating and constipation weren’t new to 54-year-old Denise Walters but became consistently worse at perimenopause until she tweaked her diet.
“Rather than cutting foods out, Nicole helped me introduce more variety into my diet and to think of how these foods were benefiting me. It felt like self-care, and making it about nourishing my body worked for me,” says Walters, who works in financial services in Sydney. “I’ve always had a fairly healthy diet but now it’s more diverse.”
Instead of the same breakfast every day, she mixes it up. Sometimes it’s kefir, oats, apple and seeds prepped the night before, or granola with fruit, or a smoothie with oats, flaxseed and banana.
“I used to have a sandwich or sushi for lunch – healthy but not much variety. Now I make salads to take to work – I’ll include prepared salad vegetables from the supermarket to save time, and add foods like four bean mix and seeds. I never ate legumes before but now I add them to bolognese sauce – and there’s more lentils than meat.
“My symptoms definitely improve when I eat this way and I feel better generally. ”
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