Written by Dr Divpreet Sacha, reviewed by Dr Phoebe Howells.

Dr Divpreet Sacha is a UK-based GP specialising in fertility and preventative medicine. She works with Neko Health, a preventative health tech company focused on early detection and lifestyle medicine. Divpreet is the creator of the Fertility Foundations programme, an evidence-based online educational programme integrating lifestyle medicine, supplements, exercise, and medical pathways to support fertility. The programme was born from her own experience navigating IVF, miscarriage, and PCOS, to help individuals feel informed and empowered throughout their fertility journey.

My Own Experience As a GP Was Not Enough

As a GP with an interest in women’s health, I thought I would have no trouble getting pregnant. I knew all the guidance we'd been taught in medical school and kept up to date throughout training, and on paper, I was doing everything right. I was wrong.

When I started struggling with my own fertility, I fell down a research rabbit hole. I discovered evidence about gut health, sperm quality, diet, and supplements that could genuinely make a difference, and it was eye-opening.

If you've ever left a GP appointment feeling like your questions about the microbiome, advanced sperm testing, or supplements were brushed aside, you're not imagining it. Most GPs simply don't talk about these things in routine fertility care. It's not because we don't care. It’s because it’s not in clinical guidelines.

The Evidence-Practice Gap

Topics like the gut microbiome, sperm DNA fragmentation, and supplementation often fall completely outside the scope of standard fertility assessment. Instead, NHS pathways focus on established causes of infertility and IVF, rather than the modifiable lifestyle or microbiome factors that research is increasingly highlighting.

There are studies showing causal links between specific gut bacteria and male infertility, abnormal sperm parameters, and reproductive inflammation. There's solid evidence that the Mediterranean diet improves IVF outcomes, including higher clinical pregnancy and live birth rates. We know that supplements like CoQ10, L-carnitine, and antioxidants can significantly improve sperm quality and conception rates.

But none of this is routinely discussed in GP surgeries. Why?

Why the Research Hasn't Reached Your GP

NICE guidance prioritises cost-effectiveness.

The National Institute for Health and Care Excellence (NICE) sets the clinical guidelines that most GPs follow, and cost-effectiveness is at the heart of every decision. The NHS has finite resources, so NICE has to prioritise interventions that deliver the best health outcomes for the money spent.

For something to become part of routine guidelines, it needs to clear thresholds: large-scale randomised controlled trials showing not just that it works, but that it's affordable and practical to implement across the NHS. This includes having clear treatment pathways for when test results come back abnormal.

Right now, things like microbiome profiling and sperm DNA fragmentation testing aren't routinely offered because they haven't yet met NICE's threshold for widespread NHS implementation. It's not that the research isn't valuable; it's that NICE has a very restricted remit in what they do and don't consider.

The irony is that simple lifestyle interventions, like dietary changes or targeted supplementation, might actually save money in the long run by improving natural conception rates and reducing IVF cycles. However, without funding for large clinical trials, they will continue to remain outside standard NHS care.

There's a time lag between research and clinical practice

Even when good evidence exists, it can take years, sometimes over a decade, for it to filter into routine practice. GPs are trained on established guidelines. Unless something becomes part of NICE or Royal College guidance, it simply doesn't make it into our day-to-day practice.

Most of the research I found was observational studies, pilot trials, and systematic reviews; all showing similar findings but not yet translated into clear clinical protocols that are integrated into national or local guidelines. Without standardised NHS guidance, it's difficult for GPs to know what to advise, at what dose, or for how long.

Male fertility research has been historically underfunded

Research into male infertility has lagged behind female fertility research for decades. Funding and research priorities have historically focused on female factors and IVF, leaving significant gaps in our understanding of male factors, environmental influences, and lifestyle modifications.

This means that even though emerging evidence suggests factors like the gut-testis axis, sperm DNA integrity, and microbiome health could be important, the research simply hasn't been widespread enough to change clinical practice yet.

The Supplement Problem

There is evidence that certain supplements can improve both egg and sperm quality: CoQ10, L-carnitine, antioxidants, omega-3, and methylfolate. The supplement market is enormous though, unregulated in many ways, and the quality varies wildly between brands.

Cheaper forms of vitamins and minerals are often poorly absorbed. Doses in many off-the-shelf supplements are too low to be therapeutic. Some products use folic acid instead of methylfolate, which matters if you have MTHFR gene variants. Without clear NHS guidance on which supplements to recommend, at what dose, and in what form, NICE & local GP pathways won’t have any mention of supplements, which means GPs simply don't feel confident discussing them.

Why This Matters

When modifiable factors like diet, gut health, and sperm quality aren't routinely addressed, people miss out on opportunities for early intervention. Simple changes could make a real difference. Eating a Mediterranean-style diet, reducing ultra-processed foods, and taking evidence-based supplements at therapeutic doses. These things might improve natural conception rates, or improve IVF outcomes. 

Research shows that adherence to the Mediterranean diet is associated with better IVF outcomes, including increased numbers of good-quality embryos and higher live birth rates. Studies demonstrate that gut health influences testosterone levels, sperm quality, and reproductive inflammation. We have systematic reviews showing that nutritional therapies significantly improve sperm parameters and pregnancy rates.

If your GP doesn't know about this research, or doesn't have the time to discuss it, you're left to figure it out yourself.

What Can You Do?

Educate yourself, but be selective about sources. Not everything online is evidence-based. Look for organisations that review their evidence base regularly and are transparent about their research. Markers of trust include the PIF TICK accreditation, the UK’s gold-standard for reliable health information. 

Don't expect your GP to have all the answers. This simply isn't part of standard training or guidance. If you're struggling with fertility, consider seeing a fertility-focused nutritionist or specialist who stays current with the latest research.

Focus on what you can control. A Mediterranean-style diet rich in vegetables, fruits, wholegrains, oily fish, nuts, seeds, and olive oil is one of the most evidence-based things you can do for fertility. It's anti-inflammatory, rich in antioxidants, and supports both egg and sperm quality.

Support your gut health. Eat more fibre, incorporate fermented foods like yoghurt and kefir, aim for 20 to 30 different plant foods each week, and include polyphenol-rich foods like berries, dark chocolate, olive oil, and spices. Limit ultra-processed foods, which can feed harmful bacteria and worsen inflammation.

Choose supplements carefully. If you're going to supplement, look for products formulated on robust evidence, with therapeutic doses and bioavailable forms. Not all supplements are created equal. For example, cheaper CoQ10 formulations are poorly absorbed, whilst patented forms like MicroActive CoQ10 have been shown to be 3.7 times better absorbed than standard versions.

Key Takeaways

• The gap between what research shows and GP guidelines exists due to a lack of research and a focus on cost-effectiveness, which means there's often a frustrating lag between emerging science and routine care, particularly in areas like male fertility and the microbiome.

• As a GP who's been through my own fertility journey, I can tell you: the evidence is there. It's just not yet part of standard practice. Gut health, sperm quality, and evidence-based supplementation aren't magic solutions, but they are important pieces of the puzzle.

• There are actionable steps you can take to take control of your situation and make positive changes for your health and wellbeing. Support, education, and resources are available to empower you with knowledge.