Sliced Bread

What's the best way to keep your home cool?
As heatwave after heatwave pushes temperatures higher across the UK and Europe, air conditioning has become a serious topic. Listener Rachel is one of many people who have turned to a portable air conditioner for relief. About the size of a dehumidifier, these units cool a room by drawing in warm air, chilling it, and venting the excess heat outside through a hose, usually attached to a window.
But with hotter summers forecast, Rachel is wondering whether it's worth investing in a fixed, or "split", air conditioning system instead. These systems use an indoor unit paired with an outdoor condenser and are increasingly common in homes across Europe. She wants to know: how much do they cost to buy and run? Are they difficult to install? And how noisy are they in everyday use?
Then there are the cheaper "air coolers" that claim to lower temperatures by blowing air over cold water or ice. Do they genuinely cool a room, or are they simply fans with clever marketing?
To find out, presenter Greg Foot is joined by Rachel and Professor Richard Fitton, Technical Director of the Energy House 2.0 test facility at the University of Salford.
All of our episodes start with your suggestions. If you've spotted an advert, trend or wonder product that claims to make you happier, healthier or greener, email us at sliced.bread@bbc.co.uk or send us a voice note on WhatsApp: 07543 306807.
RESEARCHER: JULIA RAVEY
PRODUCERS: SIMON HOBAN AND GREG FOOT

Can you really learn a new language from apps like Duolingo?

Sliced Bread listener Nathan Phelps has been teaching himself Japanese. He’s tried textbooks, tutors, and crucially, language apps on his phone - and he came to us because he’s seen these apps claiming to be “backed by science” to help you “learn a new language, fast”. More recently he’s even seen apps boast about “AI powered features” to help you practice your language skills, available on premium subscriptions.
Nathan wants to know: are language apps an effective way to learn? How do they compare to other ways of learning? And can AI really supercharge your language skills?

To find out more, presenter Greg Foot is joined by Professor Elizabeth Wonnacott, Professor of Language Science at the University of Oxford and Director of the Language Learning Lab in their Department of Education.

All of our episodes start with YOUR suggestions. If you’ve seen an ad, trend or wonder product promising to make you happier, healthier or greener, email us at sliced.bread@bbc.co.uk OR send a voice note to our WhatsApp number, 07543 306807.

RESEARCHER: JULIA RAVEY
PRODUCERS: PHIL SANSOM AND GREG FOOT

Which is the most hygienic for cleaning your kitchen?
Most of us will be familiar with the cheap packs of coloured kitchen sponges with the abrasive tops, used for washing dishes and wiping surfaces. But could they be harbouring a host of bacterial baddies?
Listener Caroline wants to know as she uses them regularly and even goes as far as running them through the washing machine to keep them cleaner for longer! Does that really work? And are there concerns about these sponges releasing microplastics? Would alternatives like cloths or brushes be a better option?
To answer all of these questions, presenter Greg Foot is joined by Markus Egert, Professor of Microbiology and Hygiene at Furtwangen University in southwest Germany and one of the authors of a major study into the hygiene of sponges; and Vilde Snekkevik, research scientist at the Norwegian Institute for Water Research in Oslo.
All of our episodes start with YOUR suggestions. If you’ve seen an ad, trend or wonder product promising to make you happier, healthier or greener, email us at sliced.bread@bbc.co.uk OR send a voice note to our WhatsApp number, 07543 306807.
RESEARCHER: JULIA RAVEY
PRODUCERS: SIMON HOBAN AND GREG FOOT

Can robotic lawnmowers save you time without hassling hedgehogs?
Listener Pat has seen adverts for robotic lawnmowers and has lots of questions: Do they cut effectively? How do they manage with edges and flower borders? And what about avoiding wildlife and other objects in the garden?
To find out, presenter Greg Foot is joined by BBC Gardeners' World magazine's tech reviewer Harry Duncton, alongside Dr Sophie Lund-Rasmussen (aka 'Dr Hedgehog'), who has carried out research into the dangers to hedgehogs posed by robotic lawnmowers.
All of our episodes start with YOUR suggestions. If you’ve seen an ad, trend or wonder product promising to make you happier, healthier or greener, email us at sliced.bread@bbc.co.uk OR send a voice note to our WhatsApp number, 07543 306807.
RESEARCHER: JULIA RAVEY
PRODUCERS: SIMON HOBAN AND GREG FOOT

Can a test tell you what's living inside your gut - and what to do about it?
That's what listener Pete Mace asked us, kicking off a brand new series of Sliced Bread! He's seen 'gut microbiome tests' advertised by ZOE, Randox Health and others. They promise to tell you about the bacteria - and other bugs - currently making your intestines their home. Many also claim they'll use this information to make personalised diet recommendations, showing you exactly what you should and shouldn't eat to nurture the right bugs and improve your health.

Pete wants to know: what can these tests really tell you? And can they really provide a diet tailored precisely to your personal wellbeing?

To find out more, presenter Greg Foot is joined by Dr Nick Ilott, Senior Researcher and lead Bioinformatician at the Oxford Centre for Microbiome Studies; and Dr Fred Warren, group leader at the Quadram Institute who researches how gut microbes interact with food.

All of our episodes start with YOUR suggestions. If you’ve seen an ad, trend or wonder product promising to make you happier, healthier or greener, email us at sliced.bread@bbc.co.uk OR send a voice note to our WhatsApp number, 07543 306807.

RESEARCHER: JULIA RAVEY
PRODUCERS: PHIL SANSOM AND GREG FOOT